mirror/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-01-30 10:31:54 +01:00
Code Issues Projects Releases Packages Wiki Activity Actions
mariadb/storage/innobase/buf/buf0lru.cc

1410 lines
41 KiB
C++
Raw Normal View History

initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/*****************************************************************************
5.6.31
2016-06-21 14:21:03 +02:00
Copyright (c) 1995, 2016, Oracle and/or its affiliates. All Rights Reserved.
MDEV-14425 Improve the redo log for concurrency The InnoDB redo log used to be formatted in blocks of 512 bytes. The log blocks were encrypted and the checksum was calculated while holding log_sys.mutex, creating a serious scalability bottleneck. We remove the fixed-size redo log block structure altogether and essentially turn every mini-transaction into a log block of its own. This allows encryption and checksum calculations to be performed on local mtr_t::m_log buffers, before acquiring log_sys.mutex. The mutex only protects a memcpy() of the data to the shared log_sys.buf, as well as the padding of the log, in case the to-be-written part of the log would not end in a block boundary of the underlying storage. For now, the "padding" consists of writing a single NUL byte, to allow recovery and mariadb-backup to detect the end of the circular log faster. Like the previous implementation, we will overwrite the last log block over and over again, until it has been completely filled. It would be possible to write only up to the last completed block (if no more recent write was requested), or to write dummy FILE_CHECKPOINT records to fill the incomplete block, by invoking the currently disabled function log_pad(). This would require adjustments to some logic around log checkpoints, page flushing, and shutdown. An upgrade after a crash of any previous version is not supported. Logically empty log files from a previous version will be upgraded. An attempt to start up InnoDB without a valid ib_logfile0 will be refused. Previously, the redo log used to be created automatically if it was missing. Only with with innodb_force_recovery=6, it is possible to start InnoDB in read-only mode even if the log file does not exist. This allows the contents of a possibly corrupted database to be dumped. Because a prepared backup from an earlier version of mariadb-backup will create a 0-sized log file, we will allow an upgrade from such log files, provided that the FIL_PAGE_FILE_FLUSH_LSN in the system tablespace looks valid. The 512-byte log checkpoint blocks at 0x200 and 0x600 will be replaced with 64-byte log checkpoint blocks at 0x1000 and 0x2000. The start of log records will move from 0x800 to 0x3000. This allows us to use 4096-byte aligned blocks for all I/O in a future revision. We extend the MDEV-12353 redo log record format as follows. (1) Empty mini-transactions or extra NUL bytes will not be allowed. (2) The end-of-minitransaction marker (a NUL byte) will be replaced with a 1-bit sequence number, which will be toggled each time when the circular log file wraps back to the beginning. (3) After the sequence bit, a CRC-32C checksum of all data (excluding the sequence bit) will written. (4) If the log is encrypted, 8 bytes will be written before the checksum and included in it. This is part of the initialization vector (IV) of encrypted log data. (5) File names, page numbers, and checkpoint information will not be encrypted. Only the payload bytes of page-level log will be encrypted. The tablespace ID and page number will form part of the IV. (6) For padding, arbitrary-length FILE_CHECKPOINT records may be written, with all-zero payload, and with the normal end marker and checksum. The minimum size is 7 bytes, or 7+8 with innodb_encrypt_log=ON. In mariadb-backup and in Galera snapshot transfer (SST) scripts, we will no longer remove ib_logfile0 or create an empty ib_logfile0. Server startup will require a valid log file. When resizing the log, we will create a logically empty ib_logfile101 at the current LSN and use an atomic rename to replace ib_logfile0 with it. See the test innodb.log_file_size. Because there is no mandatory padding in the log file, we are able to create a dummy log file as of an arbitrary log sequence number. See the test mariabackup.huge_lsn. The parameter innodb_log_write_ahead_size and the INFORMATION_SCHEMA.INNODB_METRICS counter log_padded will be removed. The minimum value of innodb_log_buffer_size will be increased to 2MiB (because log_sys.buf will replace recv_sys.buf) and the increment adjusted to 4096 bytes (the maximum log block size). The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed: os_log_fsyncs os_log_pending_fsyncs log_pending_log_flushes log_pending_checkpoint_writes The following status variables will be removed: Innodb_os_log_fsyncs (this is included in Innodb_data_fsyncs) Innodb_os_log_pending_fsyncs (this was limited to at most 1 by design) log_sys.get_block_size(): Return the physical block size of the log file. This is only implemented on Linux and Microsoft Windows for now, and for the power-of-2 block sizes between 64 and 4096 bytes (the minimum and maximum size of a checkpoint block). If the block size is anything else, the traditional 512-byte size will be used via normal file system buffering. If the file system buffers can be bypassed, a message like the following will be issued: InnoDB: File system buffers for log disabled (block size=512 bytes) InnoDB: File system buffers for log disabled (block size=4096 bytes) This has been tested on Linux and Microsoft Windows with both sizes. On Linux, only enable O_DIRECT on the log for innodb_flush_method=O_DSYNC. Tests in 3 different environments where the log is stored in a device with a physical block size of 512 bytes are yielding better throughput without O_DIRECT. This could be due to the fact that in the event the last log block is being overwritten (if multiple transactions would become durable at the same time, and each of will write a small number of bytes to the last log block), it should be faster to re-copy data from log_sys.buf or log_sys.flush_buf to the kernel buffer, to be finally written at fdatasync() time. The parameter innodb_flush_method=O_DSYNC will imply O_DIRECT for data files. This option will enable O_DIRECT on the log file on Linux. It may be unsafe to use when the storage device does not support FUA (Force Unit Access) mode. When the server is compiled WITH_PMEM=ON, we will use memory-mapped I/O for the log file if the log resides on a "mount -o dax" device. We will identify PMEM in a start-up message: InnoDB: log sequence number 0 (memory-mapped); transaction id 3 On Linux, we will also invoke mmap() on any ib_logfile0 that resides in /dev/shm, effectively treating the log file as persistent memory. This should speed up "./mtr --mem" and increase the test coverage of PMEM on non-PMEM hardware. It also allows users to estimate how much the performance would be improved by installing persistent memory. On other tmpfs file systems such as /run, we will not use mmap(). mariadb-backup: Eliminated several variables. We will refer directly to recv_sys and log_sys. backup_wait_for_lsn(): Detect non-progress of xtrabackup_copy_logfile(). In this new log format with arbitrary-sized blocks, we can only detect log file overrun indirectly, by observing that the scanned log sequence number is not advancing. xtrabackup_copy_logfile(): On PMEM, do not modify the sequence bit, because we are not allowed to modify the server's log file, and our memory mapping is read-only. trx_flush_log_if_needed_low(): Do not use the callback on pmem. Using neither flush_lock nor write_lock around PMEM writes seems to yield the best performance. The pmem_persist() calls may still be somewhat slower than the pwrite() and fdatasync() based interface (PMEM mounted without -o dax). recv_sys_t::buf: Remove. We will use log_sys.buf for parsing. recv_sys_t::MTR_SIZE_MAX: Replaces RECV_SCAN_SIZE. recv_sys_t::file_checkpoint: Renamed from mlog_checkpoint_lsn. recv_sys_t, log_sys_t: Removed many data members. recv_sys.lsn: Renamed from recv_sys.recovered_lsn. recv_sys.offset: Renamed from recv_sys.recovered_offset. log_sys.buf_size: Replaces srv_log_buffer_size. recv_buf: A smart pointer that wraps log_sys.buf[recv_sys.offset] when the buffer is being allocated from the memory heap. recv_ring: A smart pointer that wraps a circular log_sys.buf[] that is backed by ib_logfile0. The pointer will wrap from recv_sys.len (log_sys.file_size) to log_sys.START_OFFSET. For the record that wraps around, we may copy file name or record payload data to the auxiliary buffer decrypt_buf in order to have a contiguous block of memory. The maximum size of a record is less than innodb_page_size bytes. recv_sys_t::parse(): Take the smart pointer as a template parameter. Do not temporarily add a trailing NUL byte to FILE_ records, because we are not supposed to modify the memory-mapped log file. (It is attached in read-write mode already during recovery.) recv_sys_t::parse_mtr(): Wrapper for recv_sys_t::parse(). recv_sys_t::parse_pmem(): Like parse_mtr(), but if PREMATURE_EOF would be returned on PMEM, use recv_ring to wrap around the buffer to the start. mtr_t::finish_write(), log_close(): Do not enforce log_sys.max_buf_free on PMEM, because it has no meaning on the mmap-based log. log_sys.write_to_buf: Count writes to log_sys.buf. Replaces srv_stats.log_write_requests and export_vars.innodb_log_write_requests. Protected by log_sys.mutex. Updated consistently in log_close(). Previously, mtr_t::commit() conditionally updated the count, which was inconsistent. log_sys.write_to_log: Count swaps of log_sys.buf and log_sys.flush_buf, for writing to log_sys.log (the ib_logfile0). Replaces srv_stats.log_writes and export_vars.innodb_log_writes. Protected by log_sys.mutex. log_sys.waits: Count waits in append_prepare(). Replaces srv_stats.log_waits and export_vars.innodb_log_waits. recv_recover_page(): Do not unnecessarily acquire log_sys.flush_order_mutex. We are inserting the blocks in arbitary order anyway, to be adjusted in recv_sys.apply(true). We will change the definition of flush_lock and write_lock to avoid potential false sharing. Depending on sizeof(log_sys) and CPU_LEVEL1_DCACHE_LINESIZE, the flush_lock and write_lock could share a cache line with each other or with the last data members of log_sys. Thanks to Matthias Leich for providing https://rr-project.org traces for various failures during the development, and to Thirunarayanan Balathandayuthapani for his help in debugging some of the recovery code. And thanks to the developers of the rr debugger for a tool without which extensive changes to InnoDB would be very challenging to get right. Thanks to Vladislav Vaintroub for useful feedback and to him, Axel Schwenke and Krunal Bauskar for testing the performance.
2022-01-21 16:03:47 +02:00
Copyright (c) 2017, 2022, MariaDB Corporation.
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc.,
Update FSF address
2019-05-11 19:25:02 +03:00
51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
*****************************************************************************/
/**************************************************//**
@file buf/buf0lru.cc
The database buffer replacement algorithm
Created 11/5/1995 Heikki Tuuri
*******************************************************/
#include "buf0lru.h"
#include "fil0fil.h"
#include "btr0btr.h"
#include "buf0buddy.h"
#include "buf0buf.h"
#include "buf0flu.h"
#include "buf0rea.h"
#include "btr0sea.h"
#include "os0file.h"
#include "page0zip.h"
#include "log0recv.h"
#include "srv0srv.h"
#include "srv0mon.h"
MDEV-21452: Replace ib_mutex_t with mysql_mutex_t SHOW ENGINE INNODB MUTEX functionality is completely removed, as are the InnoDB latching order checks. We will enforce innodb_fatal_semaphore_wait_threshold only for dict_sys.mutex and lock_sys.mutex. dict_sys_t::mutex_lock(): A single entry point for dict_sys.mutex. lock_sys_t::mutex_lock(): A single entry point for lock_sys.mutex. FIXME: srv_sys should be removed altogether; it is duplicating tpool functionality. fil_crypt_threads_init(): To prevent SAFE_MUTEX warnings, we must not hold fil_system.mutex. fil_close_all_files(): To prevent SAFE_MUTEX warnings for fil_space_destroy_crypt_data(), we must not hold fil_system.mutex while invoking fil_space_free_low() on a detached tablespace.
2020-12-04 19:02:58 +02:00
#include "my_cpu.h"
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
/** Flush this many pages in buf_LRU_get_free_block() */
size_t innodb_lru_flush_size;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/** The number of blocks from the LRU_old pointer onward, including
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
the block pointed to, must be buf_pool.LRU_old_ratio/BUF_LRU_OLD_RATIO_DIV
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
of the whole LRU list length, except that the tolerance defined below
is allowed. Note that the tolerance must be small enough such that for
even the BUF_LRU_OLD_MIN_LEN long LRU list, the LRU_old pointer is not
allowed to point to either end of the LRU list. */
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
static constexpr ulint BUF_LRU_OLD_TOLERANCE = 20;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/** The minimum amount of non-old blocks when the LRU_old list exists
(that is, when there are more than BUF_LRU_OLD_MIN_LEN blocks).
@see buf_LRU_old_adjust_len */
#define BUF_LRU_NON_OLD_MIN_LEN 5
/** If we switch on the InnoDB monitor because there are too few available
frames in the buffer pool, we set this to TRUE */
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
static bool buf_lru_switched_on_innodb_mon = false;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/******************************************************************//**
These statistics are not 'of' LRU but 'for' LRU. We keep count of I/O
and page_zip_decompress() operations. Based on the statistics,
buf_LRU_evict_from_unzip_LRU() decides if we want to evict from
unzip_LRU or the regular LRU. From unzip_LRU, we will only evict the
uncompressed frame (meaning we can evict dirty blocks as well). From
the regular LRU, we will evict the entire block (i.e.: both the
uncompressed and compressed data), which must be clean. */
/* @{ */
/** Number of intervals for which we keep the history of these stats.
MDEV-24280 InnoDB triggers too many independent periodic tasks A side effect of MDEV-16264 is that a large number of threads will be created at server startup, to be destroyed after a minute or two. One source of such thread creation is srv_start_periodic_timer(). InnoDB is creating 3 periodic tasks: srv_master_callback (1Hz) srv_error_monitor_task (1Hz), and srv_monitor_task (0.2Hz). It appears that we can merge srv_error_monitor_task and srv_monitor_task and have them invoked 4 times per minute (every 15 seconds). This will affect our ability to enforce innodb_fatal_semaphore_wait_threshold and some computations around BUF_LRU_STAT_N_INTERVAL. We could remove srv_master_callback along with the DROP TABLE queue at some point of time in the future. We must keep it independent of the innodb_fatal_semaphore_wait_threshold detection, because the background DROP TABLE queue could get stuck due to dict_sys being locked by another thread. For now, srv_master_callback must be invoked once per second, so that innodb_flush_log_at_timeout=1 can work. BUF_LRU_STAT_N_INTERVAL: Reduce the precision and extend the time from 50*1 second to 4*15 seconds. srv_error_monitor_timer: Remove. MAX_MUTEX_NOWAIT: Increase from 20*1 second to 2*15 seconds. srv_refresh_innodb_monitor_stats(): Avoid a repeated call to time(NULL). Change the interval to less than 60 seconds. srv_monitor(): Renamed from srv_monitor_task. srv_monitor_task(): Renamed from srv_error_monitor_task(). Invoked only once in 15 seconds. Invoke also srv_monitor(). Increase the fatal_cnt threshold from 10*1 second to 1*15 seconds. sync_array_print_long_waits_low(): Invoke time(NULL) only once. Remove a bogus message about printouts for 30 seconds. Those printouts were effectively already disabled in MDEV-16264 (commit 5e62b6a5e06eb02cbde1e34e95e26f42d87fce02).
2020-11-25 16:54:00 +02:00
Updated at SRV_MONITOR_INTERVAL (the buf_LRU_stat_update() call rate). */
static constexpr ulint BUF_LRU_STAT_N_INTERVAL= 4;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/** Co-efficient with which we multiply I/O operations to equate them
with page_zip_decompress() operations. */
MDEV-24280 InnoDB triggers too many independent periodic tasks A side effect of MDEV-16264 is that a large number of threads will be created at server startup, to be destroyed after a minute or two. One source of such thread creation is srv_start_periodic_timer(). InnoDB is creating 3 periodic tasks: srv_master_callback (1Hz) srv_error_monitor_task (1Hz), and srv_monitor_task (0.2Hz). It appears that we can merge srv_error_monitor_task and srv_monitor_task and have them invoked 4 times per minute (every 15 seconds). This will affect our ability to enforce innodb_fatal_semaphore_wait_threshold and some computations around BUF_LRU_STAT_N_INTERVAL. We could remove srv_master_callback along with the DROP TABLE queue at some point of time in the future. We must keep it independent of the innodb_fatal_semaphore_wait_threshold detection, because the background DROP TABLE queue could get stuck due to dict_sys being locked by another thread. For now, srv_master_callback must be invoked once per second, so that innodb_flush_log_at_timeout=1 can work. BUF_LRU_STAT_N_INTERVAL: Reduce the precision and extend the time from 50*1 second to 4*15 seconds. srv_error_monitor_timer: Remove. MAX_MUTEX_NOWAIT: Increase from 20*1 second to 2*15 seconds. srv_refresh_innodb_monitor_stats(): Avoid a repeated call to time(NULL). Change the interval to less than 60 seconds. srv_monitor(): Renamed from srv_monitor_task. srv_monitor_task(): Renamed from srv_error_monitor_task(). Invoked only once in 15 seconds. Invoke also srv_monitor(). Increase the fatal_cnt threshold from 10*1 second to 1*15 seconds. sync_array_print_long_waits_low(): Invoke time(NULL) only once. Remove a bogus message about printouts for 30 seconds. Those printouts were effectively already disabled in MDEV-16264 (commit 5e62b6a5e06eb02cbde1e34e95e26f42d87fce02).
2020-11-25 16:54:00 +02:00
static constexpr ulint BUF_LRU_IO_TO_UNZIP_FACTOR= 50;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/** Sampled values buf_LRU_stat_cur.
Not protected by any mutex. Updated by buf_LRU_stat_update(). */
static buf_LRU_stat_t buf_LRU_stat_arr[BUF_LRU_STAT_N_INTERVAL];
/** Cursor to buf_LRU_stat_arr[] that is updated in a round-robin fashion. */
static ulint buf_LRU_stat_arr_ind;
/** Current operation counters. Not protected by any mutex. Cleared
by buf_LRU_stat_update(). */
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
buf_LRU_stat_t buf_LRU_stat_cur;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/** Running sum of past values of buf_LRU_stat_cur.
Updated by buf_LRU_stat_update(). Not Protected by any mutex. */
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
buf_LRU_stat_t buf_LRU_stat_sum;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* @} */
/** @name Heuristics for detecting index scan @{ */
/** Move blocks to "new" LRU list only if the first access was at
least this many milliseconds ago. Not protected by any mutex or latch. */
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
uint buf_LRU_old_threshold_ms;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* @} */
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
/** Remove bpage from buf_pool.LRU and buf_pool.page_hash.
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
If !bpage->frame && bpage->oldest_modification() <= 1,
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
the object will be freed.
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
@param bpage buffer block
@param id page identifier
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
@param chain locked buf_pool.page_hash chain (will be released here)
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
@param zip whether bpage->zip of BUF_BLOCK_FILE_PAGE should be freed
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
If a compressed page is freed other compressed pages may be relocated.
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
@retval true if bpage with bpage->frame was removed from page_hash. The
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
caller needs to free the page to the free list
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
@retval false if block without bpage->frame was removed from page_hash. In
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
this case the block is already returned to the buddy allocator. */
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
static bool buf_LRU_block_remove_hashed(buf_page_t *bpage, const page_id_t id,
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
buf_pool_t::hash_chain &chain,
bool zip);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
/** Free a block to buf_pool */
static void buf_LRU_block_free_hashed_page(buf_block_t *block)
{
block->page.free_file_page();
buf_LRU_block_free_non_file_page(block);
}
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
/** Increase LRU size in bytes by the page size.
@param[in] bpage control block */
static inline void incr_LRU_size_in_bytes(const buf_page_t* bpage)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_assert_owner(&buf_pool.mutex);
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.stat.LRU_bytes += bpage->physical_size();
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
ut_ad(buf_pool.stat.LRU_bytes <= buf_pool.curr_pool_size);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
/** @return whether the unzip_LRU list should be used for evicting a victim
instead of the general LRU list */
bool buf_LRU_evict_from_unzip_LRU()
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_assert_owner(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* If the unzip_LRU list is empty, we can only use the LRU. */
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
if (UT_LIST_GET_LEN(buf_pool.unzip_LRU) == 0) {
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
return false;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
/* If unzip_LRU is at most 10% of the size of the LRU list,
then use the LRU. This slack allows us to keep hot
decompressed pages in the buffer pool. */
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
if (UT_LIST_GET_LEN(buf_pool.unzip_LRU)
<= UT_LIST_GET_LEN(buf_pool.LRU) / 10) {
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
return false;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
/* If eviction hasn't started yet, we assume by default
that a workload is disk bound. */
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
if (buf_pool.freed_page_clock == 0) {
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
return true;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
/* Calculate the average over past intervals, and add the values
of the current interval. */
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
ulint io_avg = buf_LRU_stat_sum.io / BUF_LRU_STAT_N_INTERVAL
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
+ buf_LRU_stat_cur.io;
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
ulint unzip_avg = buf_LRU_stat_sum.unzip / BUF_LRU_STAT_N_INTERVAL
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
+ buf_LRU_stat_cur.unzip;
/* Decide based on our formula. If the load is I/O bound
(unzip_avg is smaller than the weighted io_avg), evict an
uncompressed frame from unzip_LRU. Otherwise we assume that
the load is CPU bound and evict from the regular LRU. */
return(unzip_avg <= io_avg * BUF_LRU_IO_TO_UNZIP_FACTOR);
}
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
/** Try to free an uncompressed page of a compressed block from the unzip
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
LRU list. The compressed page is preserved, and it need not be clean.
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
@param limit maximum number of blocks to scan
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
@return true if freed */
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
static bool buf_LRU_free_from_unzip_LRU_list(ulint limit)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
if (!buf_LRU_evict_from_unzip_LRU()) {
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
return(false);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
ulint scanned = 0;
bool freed = false;
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
for (buf_block_t* block = UT_LIST_GET_LAST(buf_pool.unzip_LRU);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
block && scanned < limit; ++scanned) {
buf_block_t* prev_block = UT_LIST_GET_PREV(unzip_LRU, block);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
ut_ad(block->page.in_file());
ut_ad(block->page.belongs_to_unzip_LRU());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_ad(block->in_unzip_LRU_list);
ut_ad(block->page.in_LRU_list);
freed = buf_LRU_free_page(&block->page, false);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if (freed) {
MDEV-30089 Metrics not incremented for 1st iteration in buf_LRU_free_from_common_LRU_list() In commit a03dd94be804a4b8b1406696920834bb2c0bedbd as well as mysql/mysql-server@6ef8c343445a26aaf9ebd76d72cf57db44b481f5 the iterations were changed so that the variable "scanned" would remain 0 when the first list item qualifies for eviction. buf_LRU_free_from_unzip_LRU_list(), buf_LRU_free_from_common_LRU_list(): Increment "scanned" when a block can be freed. buf_LRU_free_from_common_LRU_list(): Remove a redundant condition. Whenever this function is invoked, buf_pool.LRU should be nonempty, hence something should always be scanned. Thanks to Jean-François Gagné for reporting this.
2022-11-28 11:34:00 +02:00
scanned++;
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
break;
}
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
block = prev_block;
}
MDEV-6936: Buffer pool list scan optimization Merged Facebook commit 617aef9f911d825e9053f3d611d0389e02031225 authored by Inaam Rana to InnoDB storage engine (not XtraDB) from https://github.com/facebook/mysql-5.6 WL#7047 - Optimize buffer pool list scans and related batch processing Reduce excessive scanning of pages when doing flush list batches. The fix is to introduce the concept of "Hazard Pointer", this reduces the time complexity of the scan from O(n*n) to O. The concept of hazard pointer is reversed in this work. Academically hazard pointer is a pointer that the thread working on it will declar such and as long as that thread is not done no other thread is allowe do anything with it. In this WL we declare the pointer as a hazard pointer and then if any thread attempts to work on it, it is allowed to do so but it has to a the hazard pointer to the next valid value. We use hazard pointer sol reverse traversal of lists within a buffer pool instance. Add an event to control the background flush thread. The background f thread wait has been converted to an os event timed wait so that it c signalled by threads that want to kick start a background flush when buffer pool is running low on free/dirty pages.
2014-11-06 13:17:11 +02:00
if (scanned) {
MONITOR_INC_VALUE_CUMULATIVE(
MONITOR_LRU_UNZIP_SEARCH_SCANNED,
MONITOR_LRU_UNZIP_SEARCH_SCANNED_NUM_CALL,
MONITOR_LRU_UNZIP_SEARCH_SCANNED_PER_CALL,
scanned);
}
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
return(freed);
}
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
/** Try to free a clean page from the common LRU list.
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
@param limit maximum number of blocks to scan
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
@return whether a page was freed */
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
static bool buf_LRU_free_from_common_LRU_list(ulint limit)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_assert_owner(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
ulint scanned = 0;
bool freed = false;
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
for (buf_page_t* bpage = buf_pool.lru_scan_itr.start();
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
bpage && scanned < limit;
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
++scanned, bpage = buf_pool.lru_scan_itr.get()) {
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
buf_page_t* prev = UT_LIST_GET_PREV(LRU, bpage);
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.lru_scan_itr.set(prev);
MDEV-6936: Buffer pool list scan optimization Merged Facebook commit 617aef9f911d825e9053f3d611d0389e02031225 authored by Inaam Rana to InnoDB storage engine (not XtraDB) from https://github.com/facebook/mysql-5.6 WL#7047 - Optimize buffer pool list scans and related batch processing Reduce excessive scanning of pages when doing flush list batches. The fix is to introduce the concept of "Hazard Pointer", this reduces the time complexity of the scan from O(n*n) to O. The concept of hazard pointer is reversed in this work. Academically hazard pointer is a pointer that the thread working on it will declar such and as long as that thread is not done no other thread is allowe do anything with it. In this WL we declare the pointer as a hazard pointer and then if any thread attempts to work on it, it is allowed to do so but it has to a the hazard pointer to the next valid value. We use hazard pointer sol reverse traversal of lists within a buffer pool instance. Add an event to control the background flush thread. The background f thread wait has been converted to an os event timed wait so that it c signalled by threads that want to kick start a background flush when buffer pool is running low on free/dirty pages.
2014-11-06 13:17:11 +02:00
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
const auto accessed = bpage->is_accessed();
MDEV-25113: Make page flushing faster buf_page_write_complete(): Reduce the buf_pool.mutex hold time, and do not acquire buf_pool.flush_list_mutex at all. Instead, mark blocks clean by setting oldest_modification to 1. Dirty pages of temporary tables will be identified by the special value 2 instead of the previous special value 1. (By design of the ib_logfile0 format, actual LSN values smaller than 2048 are not possible.) buf_LRU_free_page(), buf_pool_t::get_oldest_modification() and many other functions will remove the garbage (clean blocks) from buf_pool.flush_list while holding buf_pool.flush_list_mutex. buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaced with non-atomic variables, protected by buf_pool.mutex, to avoid unnecessary synchronization when modifying the counts. export_vars: Remove unnecessary indirection for innodb_pages_created, innodb_pages_read, innodb_pages_written.
2021-06-23 13:13:11 +03:00
if (buf_LRU_free_page(bpage, true)) {
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if (!accessed) {
/* Keep track of pages that are evicted without
ever being accessed. This gives us a measure of
the effectiveness of readahead */
++buf_pool.stat.n_ra_pages_evicted;
}
MDEV-23410 buf_LRU_scan_and_free_block() fails to stop at first freed block An unfortunate performance regression was introduced in commit b1ab211dee599eabd9a5b886fafa3adea29ae041 (MDEV-15053) that affects workloads where the working set is larger than the buffer pool. We used to terminate the loop in buf_LRU_scan_and_free_block() when we succeeded to free a replaceable buffer pool block. Due to the regression, we would keep freeing all replaceable blocks until we reach the end of the list or encounter a block that had never been accessed because it had been brought in by read-ahead.
2020-08-05 19:59:50 +03:00
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
freed = true;
MDEV-30089 Metrics not incremented for 1st iteration in buf_LRU_free_from_common_LRU_list() In commit a03dd94be804a4b8b1406696920834bb2c0bedbd as well as mysql/mysql-server@6ef8c343445a26aaf9ebd76d72cf57db44b481f5 the iterations were changed so that the variable "scanned" would remain 0 when the first list item qualifies for eviction. buf_LRU_free_from_unzip_LRU_list(), buf_LRU_free_from_common_LRU_list(): Increment "scanned" when a block can be freed. buf_LRU_free_from_common_LRU_list(): Remove a redundant condition. Whenever this function is invoked, buf_pool.LRU should be nonempty, hence something should always be scanned. Thanks to Jean-François Gagné for reporting this.
2022-11-28 11:34:00 +02:00
scanned++;
MDEV-23410 buf_LRU_scan_and_free_block() fails to stop at first freed block An unfortunate performance regression was introduced in commit b1ab211dee599eabd9a5b886fafa3adea29ae041 (MDEV-15053) that affects workloads where the working set is larger than the buffer pool. We used to terminate the loop in buf_LRU_scan_and_free_block() when we succeeded to free a replaceable buffer pool block. Due to the regression, we would keep freeing all replaceable blocks until we reach the end of the list or encounter a block that had never been accessed because it had been brought in by read-ahead.
2020-08-05 19:59:50 +03:00
break;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
}
MDEV-30089 Metrics not incremented for 1st iteration in buf_LRU_free_from_common_LRU_list() In commit a03dd94be804a4b8b1406696920834bb2c0bedbd as well as mysql/mysql-server@6ef8c343445a26aaf9ebd76d72cf57db44b481f5 the iterations were changed so that the variable "scanned" would remain 0 when the first list item qualifies for eviction. buf_LRU_free_from_unzip_LRU_list(), buf_LRU_free_from_common_LRU_list(): Increment "scanned" when a block can be freed. buf_LRU_free_from_common_LRU_list(): Remove a redundant condition. Whenever this function is invoked, buf_pool.LRU should be nonempty, hence something should always be scanned. Thanks to Jean-François Gagné for reporting this.
2022-11-28 11:34:00 +02:00
MONITOR_INC_VALUE_CUMULATIVE(
MONITOR_LRU_SEARCH_SCANNED,
MONITOR_LRU_SEARCH_SCANNED_NUM_CALL,
MONITOR_LRU_SEARCH_SCANNED_PER_CALL,
scanned);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
return(freed);
}
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
/** @return a buffer block from the buf_pool.free list
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
@retval NULL if the free list is empty */
buf_block_t* buf_LRU_get_free_only()
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
buf_block_t* block;
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_assert_owner(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
block = reinterpret_cast<buf_block_t*>(
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
UT_LIST_GET_FIRST(buf_pool.free));
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
while (block != NULL) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_ad(block->page.in_free_list);
ut_d(block->page.in_free_list = FALSE);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_ad(!block->page.oldest_modification());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_ad(!block->page.in_LRU_list);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_a(!block->page.in_file());
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
UT_LIST_REMOVE(buf_pool.free, &block->page);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-27891: SIGSEGV in InnoDB buffer pool resize During an increase in resize, the new curr_size got a value less than old_size. As n_chunks_new and n_chunks have a strong correlation to the resizing operation in progress, we can use them and remove the need for old_size. For convienece the n_chunks_new < n_chunks is now the is_shrinking function. The volatile compiler optimization on n_chunks{,_new} is removed as real mutex uses are needed. Other n_chunks_new/n_chunks methods: n_chunks_new and n_chunks almost always read and altered under the pool mutex. Exceptions are: * i_s_innodb_buffer_page_fill, * buf_pool_t::is_uncompressed (via is_blocked_field) These need reexamining for the need of a mutex, however comments indicates this already. get_n_pages has uses in buffer pool load, recover log memory exhaustion estimates and innodb status so take the minimum number of chunks for safety. The buf_pool_t::running_out function also uses curr_size/old_size. We replace this hot function calculation with just n_chunks_new. This is the new size of the chunks before the resizing occurs. If we are resizing down, we've already got the case we had previously (as the minimum). If we are resizing upwards, we are taking an optimistic view that there will be buffer chunks available for locks. As this memory allocation is occurring immediately next the resizing function it seems likely. Compiler hint UNIV_UNLIKELY removed to leave it to the branch predictor to make an informed decision. Added test case of a smaller size than the Marko/Roel original in JIRA reducing the size to 256M. SEGV hits roughly 1/10 times but its better than a 21G memory size. Reviewer: Marko
2022-02-22 17:42:59 +11:00
if (!buf_pool.is_shrinking()
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
|| UT_LIST_GET_LEN(buf_pool.withdraw)
>= buf_pool.withdraw_target
|| !buf_pool.will_be_withdrawn(block->page)) {
Bug#24346574 PAGE CLEANER THREAD, ASSERT BLOCK->N_POINTERS == 0 btr_search_drop_page_hash_index(): Do not return before ensuring that block->index=NULL, even if !btr_search_enabled. We would typically still skip acquiring the AHI latch when the AHI is disabled, because block->index would already be NULL. Only if the AHI is in the process of being disabled, we would wait for the AHI latch and then notice that block->index=NULL and return. The above bug was a regression caused in MySQL 5.7.9 by the fix of Bug#21407023: DISABLING AHI SHOULD AVOID TAKING AHI LATCH The rest of this patch improves diagnostics by adding assertions. assert_block_ahi_valid(): A debug predicate for checking that block->n_pointers!=0 implies block->index!=NULL. assert_block_ahi_empty(): A debug predicate for checking that block->n_pointers==0. buf_block_init(): Instead of assigning block->n_pointers=0, assert_block_ahi_empty(block). buf_pool_clear_hash_index(): Clarify comments, and assign block->n_pointers=0 before assigning block->index=NULL. The wrong ordering could make block->n_pointers appear incorrect in debug assertions. This bug was introduced in MySQL 5.1.52 by Bug#13006367 62487: INNODB TAKES 3 MINUTES TO CLEAN UP THE ADAPTIVE HASH INDEX AT SHUTDOWN i_s_innodb_buffer_page_get_info(): Add a comment that the IS_HASHED column in the INFORMATION_SCHEMA views INNODB_BUFFER_POOL_PAGE and INNODB_BUFFER_PAGE_LRU may show false positives (there may be no pointers after all.) ha_insert_for_fold_func(), ha_delete_hash_node(), ha_search_and_update_if_found_func(): Use atomics for updating buf_block_t::n_pointers. While buf_block_t::index is always protected by btr_search_x_lock(index), in ha_insert_for_fold_func() the n_pointers-- may belong to another dict_index_t whose btr_search_latches[] we are not holding. RB: 13879 Reviewed-by: Jimmy Yang <jimmy.yang@oracle.com>
2016-09-02 17:28:54 +03:00
/* No adaptive hash index entries may point to
a free block. */
assert_block_ahi_empty(block);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
block->page.set_state(buf_page_t::MEMORY);
MDEV-25341: innodb buffer pool soft decommit of memory When InnoDB isn't using memory its polite to other system processes to allow that memory to be used. Create buf_page_t::set_os_unused, to madvise(MADV_FREE)/ DiscardVirtualMemory innodb buffer pool pages to keep virtual mapping but allow kernel to reclaim memory. set_os_unused is called by buf_LRU_block_free_non_file_page for flushing deallocations to free up memory. set_os_used is called by buf_block_t::initialise (used by buf_page_create_low and buf_LRU_get_free_only. Move MSan (memory sanitizer) directive to be associated with set_os_{un,}used so that the correctness can be determined by instrumentation and test cases rather than relying on OS behaviour at specific times. Remove existing page information poisoning in buf_LRU_block_free_non_file_page. Tested by: Matthias Leich Reviewer: Marko Mäkelä Windows Review: Vladislav Vaintroub
2022-08-12 19:03:12 +10:00
block->page.set_os_used();
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
break;
}
/* This should be withdrawn */
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
UT_LIST_ADD_LAST(buf_pool.withdraw, &block->page);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_d(block->in_withdraw_list = true);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
block = reinterpret_cast<buf_block_t*>(
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
UT_LIST_GET_FIRST(buf_pool.free));
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
return(block);
}
/******************************************************************//**
Checks how much of buf_pool is occupied by non-data objects like
AHI, lock heaps etc. Depending on the size of non-data objects this
function will either assert or issue a warning and switch on the
status monitor. */
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
static void buf_LRU_check_size_of_non_data_objects()
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_assert_owner(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-27891: SIGSEGV in InnoDB buffer pool resize During an increase in resize, the new curr_size got a value less than old_size. As n_chunks_new and n_chunks have a strong correlation to the resizing operation in progress, we can use them and remove the need for old_size. For convienece the n_chunks_new < n_chunks is now the is_shrinking function. The volatile compiler optimization on n_chunks{,_new} is removed as real mutex uses are needed. Other n_chunks_new/n_chunks methods: n_chunks_new and n_chunks almost always read and altered under the pool mutex. Exceptions are: * i_s_innodb_buffer_page_fill, * buf_pool_t::is_uncompressed (via is_blocked_field) These need reexamining for the need of a mutex, however comments indicates this already. get_n_pages has uses in buffer pool load, recover log memory exhaustion estimates and innodb status so take the minimum number of chunks for safety. The buf_pool_t::running_out function also uses curr_size/old_size. We replace this hot function calculation with just n_chunks_new. This is the new size of the chunks before the resizing occurs. If we are resizing down, we've already got the case we had previously (as the minimum). If we are resizing upwards, we are taking an optimistic view that there will be buffer chunks available for locks. As this memory allocation is occurring immediately next the resizing function it seems likely. Compiler hint UNIV_UNLIKELY removed to leave it to the branch predictor to make an informed decision. Added test case of a smaller size than the Marko/Roel original in JIRA reducing the size to 256M. SEGV hits roughly 1/10 times but its better than a 21G memory size. Reviewer: Marko
2022-02-22 17:42:59 +11:00
if (recv_recovery_is_on() || buf_pool.n_chunks_new != buf_pool.n_chunks)
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
return;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
const auto s= UT_LIST_GET_LEN(buf_pool.free) + UT_LIST_GET_LEN(buf_pool.LRU);
if (s < buf_pool.curr_size / 20)
ib::fatal() << "Over 95 percent of the buffer pool is"
" occupied by lock heaps"
MDEV-12121 Introduce build option WITH_INNODB_AHI to disable innodb_adaptive_hash_index The InnoDB adaptive hash index is sometimes degrading the performance of InnoDB, and it is sometimes disabled to get more consistent performance. We should have a compile-time option to disable the adaptive hash index. Let us introduce two options: OPTION(WITH_INNODB_AHI "Include innodb_adaptive_hash_index" ON) OPTION(WITH_INNODB_ROOT_GUESS "Cache index root block descriptors" ON) where WITH_INNODB_AHI always implies WITH_INNODB_ROOT_GUESS. As part of this change, the misleadingly named function trx_search_latch_release_if_reserved(trx) will be replaced with the macro trx_assert_no_search_latch(trx) that will be empty unless BTR_CUR_HASH_ADAPT is defined (cmake -DWITH_INNODB_AHI=ON). We will also remove the unused column INFORMATION_SCHEMA.INNODB_TRX.TRX_ADAPTIVE_HASH_TIMEOUT. In MariaDB Server 10.1, it used to reflect the value of trx_t::search_latch_timeout which could be adjusted during row_search_for_mysql(). In 10.2, there is no such field. Other than the removal of the unused column TRX_ADAPTIVE_HASH_TIMEOUT, this is an almost non-functional change to the server when using the default build options. Some tests are adjusted so that they will work with both -DWITH_INNODB_AHI=ON and -DWITH_INNODB_AHI=OFF. The test innodb.innodb_monitor has been renamed to innodb.monitor in order to track MySQL 5.7, and the duplicate tests sys_vars.innodb_monitor_* are removed.
2017-02-23 23:05:12 +02:00
#ifdef BTR_CUR_HASH_ADAPT
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
" or the adaptive hash index"
MDEV-12121 Introduce build option WITH_INNODB_AHI to disable innodb_adaptive_hash_index The InnoDB adaptive hash index is sometimes degrading the performance of InnoDB, and it is sometimes disabled to get more consistent performance. We should have a compile-time option to disable the adaptive hash index. Let us introduce two options: OPTION(WITH_INNODB_AHI "Include innodb_adaptive_hash_index" ON) OPTION(WITH_INNODB_ROOT_GUESS "Cache index root block descriptors" ON) where WITH_INNODB_AHI always implies WITH_INNODB_ROOT_GUESS. As part of this change, the misleadingly named function trx_search_latch_release_if_reserved(trx) will be replaced with the macro trx_assert_no_search_latch(trx) that will be empty unless BTR_CUR_HASH_ADAPT is defined (cmake -DWITH_INNODB_AHI=ON). We will also remove the unused column INFORMATION_SCHEMA.INNODB_TRX.TRX_ADAPTIVE_HASH_TIMEOUT. In MariaDB Server 10.1, it used to reflect the value of trx_t::search_latch_timeout which could be adjusted during row_search_for_mysql(). In 10.2, there is no such field. Other than the removal of the unused column TRX_ADAPTIVE_HASH_TIMEOUT, this is an almost non-functional change to the server when using the default build options. Some tests are adjusted so that they will work with both -DWITH_INNODB_AHI=ON and -DWITH_INNODB_AHI=OFF. The test innodb.innodb_monitor has been renamed to innodb.monitor in order to track MySQL 5.7, and the duplicate tests sys_vars.innodb_monitor_* are removed.
2017-02-23 23:05:12 +02:00
#endif /* BTR_CUR_HASH_ADAPT */
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
"! Check that your transactions do not set too many"
" row locks, or review if innodb_buffer_pool_size="
<< (buf_pool.curr_size >> (20U - srv_page_size_shift))
<< "M could be bigger.";
if (s < buf_pool.curr_size / 3)
{
if (!buf_lru_switched_on_innodb_mon && srv_monitor_timer)
{
/* Over 67 % of the buffer pool is occupied by lock heaps or
the adaptive hash index. This may be a memory leak! */
ib::warn() << "Over 67 percent of the buffer pool is"
" occupied by lock heaps"
MDEV-12121 Introduce build option WITH_INNODB_AHI to disable innodb_adaptive_hash_index The InnoDB adaptive hash index is sometimes degrading the performance of InnoDB, and it is sometimes disabled to get more consistent performance. We should have a compile-time option to disable the adaptive hash index. Let us introduce two options: OPTION(WITH_INNODB_AHI "Include innodb_adaptive_hash_index" ON) OPTION(WITH_INNODB_ROOT_GUESS "Cache index root block descriptors" ON) where WITH_INNODB_AHI always implies WITH_INNODB_ROOT_GUESS. As part of this change, the misleadingly named function trx_search_latch_release_if_reserved(trx) will be replaced with the macro trx_assert_no_search_latch(trx) that will be empty unless BTR_CUR_HASH_ADAPT is defined (cmake -DWITH_INNODB_AHI=ON). We will also remove the unused column INFORMATION_SCHEMA.INNODB_TRX.TRX_ADAPTIVE_HASH_TIMEOUT. In MariaDB Server 10.1, it used to reflect the value of trx_t::search_latch_timeout which could be adjusted during row_search_for_mysql(). In 10.2, there is no such field. Other than the removal of the unused column TRX_ADAPTIVE_HASH_TIMEOUT, this is an almost non-functional change to the server when using the default build options. Some tests are adjusted so that they will work with both -DWITH_INNODB_AHI=ON and -DWITH_INNODB_AHI=OFF. The test innodb.innodb_monitor has been renamed to innodb.monitor in order to track MySQL 5.7, and the duplicate tests sys_vars.innodb_monitor_* are removed.
2017-02-23 23:05:12 +02:00
#ifdef BTR_CUR_HASH_ADAPT
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
" or the adaptive hash index"
MDEV-12121 Introduce build option WITH_INNODB_AHI to disable innodb_adaptive_hash_index The InnoDB adaptive hash index is sometimes degrading the performance of InnoDB, and it is sometimes disabled to get more consistent performance. We should have a compile-time option to disable the adaptive hash index. Let us introduce two options: OPTION(WITH_INNODB_AHI "Include innodb_adaptive_hash_index" ON) OPTION(WITH_INNODB_ROOT_GUESS "Cache index root block descriptors" ON) where WITH_INNODB_AHI always implies WITH_INNODB_ROOT_GUESS. As part of this change, the misleadingly named function trx_search_latch_release_if_reserved(trx) will be replaced with the macro trx_assert_no_search_latch(trx) that will be empty unless BTR_CUR_HASH_ADAPT is defined (cmake -DWITH_INNODB_AHI=ON). We will also remove the unused column INFORMATION_SCHEMA.INNODB_TRX.TRX_ADAPTIVE_HASH_TIMEOUT. In MariaDB Server 10.1, it used to reflect the value of trx_t::search_latch_timeout which could be adjusted during row_search_for_mysql(). In 10.2, there is no such field. Other than the removal of the unused column TRX_ADAPTIVE_HASH_TIMEOUT, this is an almost non-functional change to the server when using the default build options. Some tests are adjusted so that they will work with both -DWITH_INNODB_AHI=ON and -DWITH_INNODB_AHI=OFF. The test innodb.innodb_monitor has been renamed to innodb.monitor in order to track MySQL 5.7, and the duplicate tests sys_vars.innodb_monitor_* are removed.
2017-02-23 23:05:12 +02:00
#endif /* BTR_CUR_HASH_ADAPT */
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
"! Check that your transactions do not set too many row locks."
" innodb_buffer_pool_size="
<< (buf_pool.curr_size >> (20U - srv_page_size_shift))
<< "M. Starting the InnoDB Monitor to print diagnostics.";
buf_lru_switched_on_innodb_mon= true;
srv_print_innodb_monitor= TRUE;
srv_monitor_timer_schedule_now();
}
}
else if (buf_lru_switched_on_innodb_mon)
{
/* Switch off the InnoDB Monitor; this is a simple way to stop the
monitor if the situation becomes less urgent, but may also
surprise users who did SET GLOBAL innodb_status_output=ON earlier! */
buf_lru_switched_on_innodb_mon= false;
srv_print_innodb_monitor= FALSE;
}
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
/** Get a block from the buf_pool.free list.
If the list is empty, blocks will be moved from the end of buf_pool.LRU
to buf_pool.free.
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
This function is called from a user thread when it needs a clean
block to read in a page. Note that we only ever get a block from
the free list. Even when we flush a page or find a page in LRU scan
we put it to free list to be used.
* iteration 0:
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
* get a block from the buf_pool.free list, success:done
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
* if buf_pool.try_LRU_scan is set
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
* scan LRU up to 100 pages to free a clean block
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
* success:retry the free list
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
* flush up to innodb_lru_flush_size LRU blocks to data files
(until UT_LIST_GET_GEN(buf_pool.free) < innodb_lru_scan_depth)
* on buf_page_write_complete() the blocks will put on buf_pool.free list
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
* success: retry the free list
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
* subsequent iterations: same as iteration 0 except:
* scan whole LRU list
* scan LRU list even if buf_pool.try_LRU_scan is not set
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
@param have_mutex whether buf_pool.mutex is already being held
@return the free control block, in state BUF_BLOCK_MEMORY */
MDEV-26004 Excessive wait times in buf_LRU_get_free_block() buf_LRU_get_free_block(): Initially wait for a single block to be freed, signaled by buf_pool.done_free. Only if that fails and no LRU eviction flushing batch is already running, we initiate a flushing batch that should serve all threads that are currently waiting in buf_LRU_get_free_block(). Note: In an extreme case, this may introduce a performance regression at larger numbers of connections. We observed this in sysbench oltp_update_index with 512MiB buffer pool, 4GiB of data on fast NVMe, and 1000 concurrent connections, on a 20-thread CPU. The contention point appears to be buf_pool.mutex, and the improvement would turn into a regression somewhere beyond 32 concurrent connections. On slower storage, such regression was not observed; instead, the throughput was improving and maximum latency was reduced. The excessive waits were pointed out by Vladislav Vaintroub.
2021-06-24 11:01:18 +03:00
buf_block_t *buf_LRU_get_free_block(bool have_mutex)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-33613 InnoDB may still hang when temporarily running out of buffer pool By design, InnoDB has always hung when permanently running out of buffer pool, for example when several threads are waiting to allocate a block, and all of the buffer pool is buffer-fixed by the active threads. The hang that we are fixing here occurs when the buffer pool is only temporarily running out and the situation could be rescued by writing out some dirty pages or evicting some clean pages. buf_LRU_get_free_block(): Simplify the way how we wait for the buf_flush_page_cleaner thread. This fixes occasional hangs of the test encryption.innochecksum that were introduced by commit a55b951e6082a4ce9a1f2ed5ee176ea7dbbaf1f2 (MDEV-26827). To play it safe, we use a timed wait when waiting for the buf_flush_page_cleaner() thread to perform its job. Should that thread get stuck, we will invoke buf_pool.LRU_warn() in order to display a message that pages could not be freed, and keep trying to wake up the buf_flush_page_cleaner() thread. The INFORMATION_SCHEMA.INNODB_METRICS counters buffer_LRU_single_flush_failure_count and buffer_LRU_get_free_waits will be removed. The latter is represented by buffer_pool_wait_free. Also removed will be the message "InnoDB: Difficult to find free blocks in the buffer pool" because in d34479dc664d4cbd4e9dad6b0f92d7c8e55595d1 we introduced a more precise message "InnoDB: Could not free any blocks in the buffer pool" in the buf_flush_page_cleaner thread. buf_pool_t::LRU_warn(): Issue the warning message that we could not free any blocks in the buffer pool. This may also be invoked by buf_LRU_get_free_block() if buf_flush_page_cleaner() appears to be stuck. buf_pool_t::n_flush_dec(): Remove. buf_pool_t::n_flush_dec_holding_mutex(): Rename to n_flush_dec(). buf_flush_LRU_list_batch(): Increment the eviction counter for blocks of temporary, discarded or dropped tablespaces. buf_flush_LRU(): Make static, and remove the constant parameter evict=false. The only caller will be the buf_flush_page_cleaner() thread. IORequest::is_LRU(): Remove. The only case of evicting pages on write completion will be when we are writing out pages of the temporary tablespace. Those pages are not in buf_pool.flush_list, only in buf_pool.LRU. buf_page_t::flush(): Remove the parameter evict. buf_page_t::write_complete(): Change the parameter "bool temporary" to "bool persistent" and add a parameter for an already read state(). Reviewed by: Debarun Banerjee
2024-03-22 14:17:39 +02:00
bool waited= false;
MONITOR_INC(MONITOR_LRU_GET_FREE_SEARCH);
if (!have_mutex)
mysql_mutex_lock(&buf_pool.mutex);
MDEV-14776: InnoDB Monitor output generated by specific error is flooding error logs innodb/buf_LRU_get_free_block Add debug instrumentation to produce error message about no free pages. Print error message only once and do not enable innodb monitor. xtradb/buf_LRU_get_free_block Add debug instrumentation to produce error message about no free pages. Print error message only once and do not enable innodb monitor. Remove code that does not seem to be used. innodb-lru-force-no-free-page.test New test case to force produce desired error message.
2018-01-09 12:37:58 +02:00
MDEV-33613 InnoDB may still hang when temporarily running out of buffer pool By design, InnoDB has always hung when permanently running out of buffer pool, for example when several threads are waiting to allocate a block, and all of the buffer pool is buffer-fixed by the active threads. The hang that we are fixing here occurs when the buffer pool is only temporarily running out and the situation could be rescued by writing out some dirty pages or evicting some clean pages. buf_LRU_get_free_block(): Simplify the way how we wait for the buf_flush_page_cleaner thread. This fixes occasional hangs of the test encryption.innochecksum that were introduced by commit a55b951e6082a4ce9a1f2ed5ee176ea7dbbaf1f2 (MDEV-26827). To play it safe, we use a timed wait when waiting for the buf_flush_page_cleaner() thread to perform its job. Should that thread get stuck, we will invoke buf_pool.LRU_warn() in order to display a message that pages could not be freed, and keep trying to wake up the buf_flush_page_cleaner() thread. The INFORMATION_SCHEMA.INNODB_METRICS counters buffer_LRU_single_flush_failure_count and buffer_LRU_get_free_waits will be removed. The latter is represented by buffer_pool_wait_free. Also removed will be the message "InnoDB: Difficult to find free blocks in the buffer pool" because in d34479dc664d4cbd4e9dad6b0f92d7c8e55595d1 we introduced a more precise message "InnoDB: Could not free any blocks in the buffer pool" in the buf_flush_page_cleaner thread. buf_pool_t::LRU_warn(): Issue the warning message that we could not free any blocks in the buffer pool. This may also be invoked by buf_LRU_get_free_block() if buf_flush_page_cleaner() appears to be stuck. buf_pool_t::n_flush_dec(): Remove. buf_pool_t::n_flush_dec_holding_mutex(): Rename to n_flush_dec(). buf_flush_LRU_list_batch(): Increment the eviction counter for blocks of temporary, discarded or dropped tablespaces. buf_flush_LRU(): Make static, and remove the constant parameter evict=false. The only caller will be the buf_flush_page_cleaner() thread. IORequest::is_LRU(): Remove. The only case of evicting pages on write completion will be when we are writing out pages of the temporary tablespace. Those pages are not in buf_pool.flush_list, only in buf_pool.LRU. buf_page_t::flush(): Remove the parameter evict. buf_page_t::write_complete(): Change the parameter "bool temporary" to "bool persistent" and add a parameter for an already read state(). Reviewed by: Debarun Banerjee
2024-03-22 14:17:39 +02:00
buf_LRU_check_size_of_non_data_objects();
MDEV-33053 InnoDB LRU flushing does not run before running out of buffer pool buf_flush_LRU(): Display a warning if no pages could be evicted and no writes initiated. buf_pool_t::need_LRU_eviction(): Renamed from buf_pool_t::ran_out(). Check if the amount of free pages is smaller than innodb_lru_scan_depth instead of checking if it is 0. buf_flush_page_cleaner(): For the final LRU flush after a checkpoint flush, use a "budget" of innodb_io_capacity_max, like we do in the case when we are not in "furious" checkpoint flushing. Co-developed by: Debarun Banerjee Reviewed by: Debarun Banerjee Tested by: Matthias Leich
2024-01-19 12:40:16 +02:00
MDEV-33613 InnoDB may still hang when temporarily running out of buffer pool By design, InnoDB has always hung when permanently running out of buffer pool, for example when several threads are waiting to allocate a block, and all of the buffer pool is buffer-fixed by the active threads. The hang that we are fixing here occurs when the buffer pool is only temporarily running out and the situation could be rescued by writing out some dirty pages or evicting some clean pages. buf_LRU_get_free_block(): Simplify the way how we wait for the buf_flush_page_cleaner thread. This fixes occasional hangs of the test encryption.innochecksum that were introduced by commit a55b951e6082a4ce9a1f2ed5ee176ea7dbbaf1f2 (MDEV-26827). To play it safe, we use a timed wait when waiting for the buf_flush_page_cleaner() thread to perform its job. Should that thread get stuck, we will invoke buf_pool.LRU_warn() in order to display a message that pages could not be freed, and keep trying to wake up the buf_flush_page_cleaner() thread. The INFORMATION_SCHEMA.INNODB_METRICS counters buffer_LRU_single_flush_failure_count and buffer_LRU_get_free_waits will be removed. The latter is represented by buffer_pool_wait_free. Also removed will be the message "InnoDB: Difficult to find free blocks in the buffer pool" because in d34479dc664d4cbd4e9dad6b0f92d7c8e55595d1 we introduced a more precise message "InnoDB: Could not free any blocks in the buffer pool" in the buf_flush_page_cleaner thread. buf_pool_t::LRU_warn(): Issue the warning message that we could not free any blocks in the buffer pool. This may also be invoked by buf_LRU_get_free_block() if buf_flush_page_cleaner() appears to be stuck. buf_pool_t::n_flush_dec(): Remove. buf_pool_t::n_flush_dec_holding_mutex(): Rename to n_flush_dec(). buf_flush_LRU_list_batch(): Increment the eviction counter for blocks of temporary, discarded or dropped tablespaces. buf_flush_LRU(): Make static, and remove the constant parameter evict=false. The only caller will be the buf_flush_page_cleaner() thread. IORequest::is_LRU(): Remove. The only case of evicting pages on write completion will be when we are writing out pages of the temporary tablespace. Those pages are not in buf_pool.flush_list, only in buf_pool.LRU. buf_page_t::flush(): Remove the parameter evict. buf_page_t::write_complete(): Change the parameter "bool temporary" to "bool persistent" and add a parameter for an already read state(). Reviewed by: Debarun Banerjee
2024-03-22 14:17:39 +02:00
buf_block_t *block;
MDEV-33053 InnoDB LRU flushing does not run before running out of buffer pool buf_flush_LRU(): Display a warning if no pages could be evicted and no writes initiated. buf_pool_t::need_LRU_eviction(): Renamed from buf_pool_t::ran_out(). Check if the amount of free pages is smaller than innodb_lru_scan_depth instead of checking if it is 0. buf_flush_page_cleaner(): For the final LRU flush after a checkpoint flush, use a "budget" of innodb_io_capacity_max, like we do in the case when we are not in "furious" checkpoint flushing. Co-developed by: Debarun Banerjee Reviewed by: Debarun Banerjee Tested by: Matthias Leich
2024-01-19 12:40:16 +02:00
MDEV-33613 InnoDB may still hang when temporarily running out of buffer pool By design, InnoDB has always hung when permanently running out of buffer pool, for example when several threads are waiting to allocate a block, and all of the buffer pool is buffer-fixed by the active threads. The hang that we are fixing here occurs when the buffer pool is only temporarily running out and the situation could be rescued by writing out some dirty pages or evicting some clean pages. buf_LRU_get_free_block(): Simplify the way how we wait for the buf_flush_page_cleaner thread. This fixes occasional hangs of the test encryption.innochecksum that were introduced by commit a55b951e6082a4ce9a1f2ed5ee176ea7dbbaf1f2 (MDEV-26827). To play it safe, we use a timed wait when waiting for the buf_flush_page_cleaner() thread to perform its job. Should that thread get stuck, we will invoke buf_pool.LRU_warn() in order to display a message that pages could not be freed, and keep trying to wake up the buf_flush_page_cleaner() thread. The INFORMATION_SCHEMA.INNODB_METRICS counters buffer_LRU_single_flush_failure_count and buffer_LRU_get_free_waits will be removed. The latter is represented by buffer_pool_wait_free. Also removed will be the message "InnoDB: Difficult to find free blocks in the buffer pool" because in d34479dc664d4cbd4e9dad6b0f92d7c8e55595d1 we introduced a more precise message "InnoDB: Could not free any blocks in the buffer pool" in the buf_flush_page_cleaner thread. buf_pool_t::LRU_warn(): Issue the warning message that we could not free any blocks in the buffer pool. This may also be invoked by buf_LRU_get_free_block() if buf_flush_page_cleaner() appears to be stuck. buf_pool_t::n_flush_dec(): Remove. buf_pool_t::n_flush_dec_holding_mutex(): Rename to n_flush_dec(). buf_flush_LRU_list_batch(): Increment the eviction counter for blocks of temporary, discarded or dropped tablespaces. buf_flush_LRU(): Make static, and remove the constant parameter evict=false. The only caller will be the buf_flush_page_cleaner() thread. IORequest::is_LRU(): Remove. The only case of evicting pages on write completion will be when we are writing out pages of the temporary tablespace. Those pages are not in buf_pool.flush_list, only in buf_pool.LRU. buf_page_t::flush(): Remove the parameter evict. buf_page_t::write_complete(): Change the parameter "bool temporary" to "bool persistent" and add a parameter for an already read state(). Reviewed by: Debarun Banerjee
2024-03-22 14:17:39 +02:00
retry:
/* If there is a block in the free list, take it */
block= buf_LRU_get_free_only();
if (block)
{
got_block:
const ulint LRU_size= UT_LIST_GET_LEN(buf_pool.LRU);
const ulint available= UT_LIST_GET_LEN(buf_pool.free);
const ulint scan_depth= srv_LRU_scan_depth / 2;
ut_ad(LRU_size <= BUF_LRU_MIN_LEN ||
available >= scan_depth || buf_pool.need_LRU_eviction());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-33613 InnoDB may still hang when temporarily running out of buffer pool By design, InnoDB has always hung when permanently running out of buffer pool, for example when several threads are waiting to allocate a block, and all of the buffer pool is buffer-fixed by the active threads. The hang that we are fixing here occurs when the buffer pool is only temporarily running out and the situation could be rescued by writing out some dirty pages or evicting some clean pages. buf_LRU_get_free_block(): Simplify the way how we wait for the buf_flush_page_cleaner thread. This fixes occasional hangs of the test encryption.innochecksum that were introduced by commit a55b951e6082a4ce9a1f2ed5ee176ea7dbbaf1f2 (MDEV-26827). To play it safe, we use a timed wait when waiting for the buf_flush_page_cleaner() thread to perform its job. Should that thread get stuck, we will invoke buf_pool.LRU_warn() in order to display a message that pages could not be freed, and keep trying to wake up the buf_flush_page_cleaner() thread. The INFORMATION_SCHEMA.INNODB_METRICS counters buffer_LRU_single_flush_failure_count and buffer_LRU_get_free_waits will be removed. The latter is represented by buffer_pool_wait_free. Also removed will be the message "InnoDB: Difficult to find free blocks in the buffer pool" because in d34479dc664d4cbd4e9dad6b0f92d7c8e55595d1 we introduced a more precise message "InnoDB: Could not free any blocks in the buffer pool" in the buf_flush_page_cleaner thread. buf_pool_t::LRU_warn(): Issue the warning message that we could not free any blocks in the buffer pool. This may also be invoked by buf_LRU_get_free_block() if buf_flush_page_cleaner() appears to be stuck. buf_pool_t::n_flush_dec(): Remove. buf_pool_t::n_flush_dec_holding_mutex(): Rename to n_flush_dec(). buf_flush_LRU_list_batch(): Increment the eviction counter for blocks of temporary, discarded or dropped tablespaces. buf_flush_LRU(): Make static, and remove the constant parameter evict=false. The only caller will be the buf_flush_page_cleaner() thread. IORequest::is_LRU(): Remove. The only case of evicting pages on write completion will be when we are writing out pages of the temporary tablespace. Those pages are not in buf_pool.flush_list, only in buf_pool.LRU. buf_page_t::flush(): Remove the parameter evict. buf_page_t::write_complete(): Change the parameter "bool temporary" to "bool persistent" and add a parameter for an already read state(). Reviewed by: Debarun Banerjee
2024-03-22 14:17:39 +02:00
if (UNIV_UNLIKELY(available < scan_depth) && LRU_size > BUF_LRU_MIN_LEN)
{
mysql_mutex_lock(&buf_pool.flush_list_mutex);
if (!buf_pool.page_cleaner_active())
buf_pool.page_cleaner_wakeup(true);
mysql_mutex_unlock(&buf_pool.flush_list_mutex);
}
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
MDEV-33613 InnoDB may still hang when temporarily running out of buffer pool By design, InnoDB has always hung when permanently running out of buffer pool, for example when several threads are waiting to allocate a block, and all of the buffer pool is buffer-fixed by the active threads. The hang that we are fixing here occurs when the buffer pool is only temporarily running out and the situation could be rescued by writing out some dirty pages or evicting some clean pages. buf_LRU_get_free_block(): Simplify the way how we wait for the buf_flush_page_cleaner thread. This fixes occasional hangs of the test encryption.innochecksum that were introduced by commit a55b951e6082a4ce9a1f2ed5ee176ea7dbbaf1f2 (MDEV-26827). To play it safe, we use a timed wait when waiting for the buf_flush_page_cleaner() thread to perform its job. Should that thread get stuck, we will invoke buf_pool.LRU_warn() in order to display a message that pages could not be freed, and keep trying to wake up the buf_flush_page_cleaner() thread. The INFORMATION_SCHEMA.INNODB_METRICS counters buffer_LRU_single_flush_failure_count and buffer_LRU_get_free_waits will be removed. The latter is represented by buffer_pool_wait_free. Also removed will be the message "InnoDB: Difficult to find free blocks in the buffer pool" because in d34479dc664d4cbd4e9dad6b0f92d7c8e55595d1 we introduced a more precise message "InnoDB: Could not free any blocks in the buffer pool" in the buf_flush_page_cleaner thread. buf_pool_t::LRU_warn(): Issue the warning message that we could not free any blocks in the buffer pool. This may also be invoked by buf_LRU_get_free_block() if buf_flush_page_cleaner() appears to be stuck. buf_pool_t::n_flush_dec(): Remove. buf_pool_t::n_flush_dec_holding_mutex(): Rename to n_flush_dec(). buf_flush_LRU_list_batch(): Increment the eviction counter for blocks of temporary, discarded or dropped tablespaces. buf_flush_LRU(): Make static, and remove the constant parameter evict=false. The only caller will be the buf_flush_page_cleaner() thread. IORequest::is_LRU(): Remove. The only case of evicting pages on write completion will be when we are writing out pages of the temporary tablespace. Those pages are not in buf_pool.flush_list, only in buf_pool.LRU. buf_page_t::flush(): Remove the parameter evict. buf_page_t::write_complete(): Change the parameter "bool temporary" to "bool persistent" and add a parameter for an already read state(). Reviewed by: Debarun Banerjee
2024-03-22 14:17:39 +02:00
if (!have_mutex)
mysql_mutex_unlock(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-33613 InnoDB may still hang when temporarily running out of buffer pool By design, InnoDB has always hung when permanently running out of buffer pool, for example when several threads are waiting to allocate a block, and all of the buffer pool is buffer-fixed by the active threads. The hang that we are fixing here occurs when the buffer pool is only temporarily running out and the situation could be rescued by writing out some dirty pages or evicting some clean pages. buf_LRU_get_free_block(): Simplify the way how we wait for the buf_flush_page_cleaner thread. This fixes occasional hangs of the test encryption.innochecksum that were introduced by commit a55b951e6082a4ce9a1f2ed5ee176ea7dbbaf1f2 (MDEV-26827). To play it safe, we use a timed wait when waiting for the buf_flush_page_cleaner() thread to perform its job. Should that thread get stuck, we will invoke buf_pool.LRU_warn() in order to display a message that pages could not be freed, and keep trying to wake up the buf_flush_page_cleaner() thread. The INFORMATION_SCHEMA.INNODB_METRICS counters buffer_LRU_single_flush_failure_count and buffer_LRU_get_free_waits will be removed. The latter is represented by buffer_pool_wait_free. Also removed will be the message "InnoDB: Difficult to find free blocks in the buffer pool" because in d34479dc664d4cbd4e9dad6b0f92d7c8e55595d1 we introduced a more precise message "InnoDB: Could not free any blocks in the buffer pool" in the buf_flush_page_cleaner thread. buf_pool_t::LRU_warn(): Issue the warning message that we could not free any blocks in the buffer pool. This may also be invoked by buf_LRU_get_free_block() if buf_flush_page_cleaner() appears to be stuck. buf_pool_t::n_flush_dec(): Remove. buf_pool_t::n_flush_dec_holding_mutex(): Rename to n_flush_dec(). buf_flush_LRU_list_batch(): Increment the eviction counter for blocks of temporary, discarded or dropped tablespaces. buf_flush_LRU(): Make static, and remove the constant parameter evict=false. The only caller will be the buf_flush_page_cleaner() thread. IORequest::is_LRU(): Remove. The only case of evicting pages on write completion will be when we are writing out pages of the temporary tablespace. Those pages are not in buf_pool.flush_list, only in buf_pool.LRU. buf_page_t::flush(): Remove the parameter evict. buf_page_t::write_complete(): Change the parameter "bool temporary" to "bool persistent" and add a parameter for an already read state(). Reviewed by: Debarun Banerjee
2024-03-22 14:17:39 +02:00
block->page.zip.clear();
return block;
}
MDEV-26004 Excessive wait times in buf_LRU_get_free_block() buf_LRU_get_free_block(): Initially wait for a single block to be freed, signaled by buf_pool.done_free. Only if that fails and no LRU eviction flushing batch is already running, we initiate a flushing batch that should serve all threads that are currently waiting in buf_LRU_get_free_block(). Note: In an extreme case, this may introduce a performance regression at larger numbers of connections. We observed this in sysbench oltp_update_index with 512MiB buffer pool, 4GiB of data on fast NVMe, and 1000 concurrent connections, on a 20-thread CPU. The contention point appears to be buf_pool.mutex, and the improvement would turn into a regression somewhere beyond 32 concurrent connections. On slower storage, such regression was not observed; instead, the throughput was improving and maximum latency was reduced. The excessive waits were pointed out by Vladislav Vaintroub.
2021-06-24 11:01:18 +03:00
MDEV-33613 InnoDB may still hang when temporarily running out of buffer pool By design, InnoDB has always hung when permanently running out of buffer pool, for example when several threads are waiting to allocate a block, and all of the buffer pool is buffer-fixed by the active threads. The hang that we are fixing here occurs when the buffer pool is only temporarily running out and the situation could be rescued by writing out some dirty pages or evicting some clean pages. buf_LRU_get_free_block(): Simplify the way how we wait for the buf_flush_page_cleaner thread. This fixes occasional hangs of the test encryption.innochecksum that were introduced by commit a55b951e6082a4ce9a1f2ed5ee176ea7dbbaf1f2 (MDEV-26827). To play it safe, we use a timed wait when waiting for the buf_flush_page_cleaner() thread to perform its job. Should that thread get stuck, we will invoke buf_pool.LRU_warn() in order to display a message that pages could not be freed, and keep trying to wake up the buf_flush_page_cleaner() thread. The INFORMATION_SCHEMA.INNODB_METRICS counters buffer_LRU_single_flush_failure_count and buffer_LRU_get_free_waits will be removed. The latter is represented by buffer_pool_wait_free. Also removed will be the message "InnoDB: Difficult to find free blocks in the buffer pool" because in d34479dc664d4cbd4e9dad6b0f92d7c8e55595d1 we introduced a more precise message "InnoDB: Could not free any blocks in the buffer pool" in the buf_flush_page_cleaner thread. buf_pool_t::LRU_warn(): Issue the warning message that we could not free any blocks in the buffer pool. This may also be invoked by buf_LRU_get_free_block() if buf_flush_page_cleaner() appears to be stuck. buf_pool_t::n_flush_dec(): Remove. buf_pool_t::n_flush_dec_holding_mutex(): Rename to n_flush_dec(). buf_flush_LRU_list_batch(): Increment the eviction counter for blocks of temporary, discarded or dropped tablespaces. buf_flush_LRU(): Make static, and remove the constant parameter evict=false. The only caller will be the buf_flush_page_cleaner() thread. IORequest::is_LRU(): Remove. The only case of evicting pages on write completion will be when we are writing out pages of the temporary tablespace. Those pages are not in buf_pool.flush_list, only in buf_pool.LRU. buf_page_t::flush(): Remove the parameter evict. buf_page_t::write_complete(): Change the parameter "bool temporary" to "bool persistent" and add a parameter for an already read state(). Reviewed by: Debarun Banerjee
2024-03-22 14:17:39 +02:00
MONITOR_INC(MONITOR_LRU_GET_FREE_LOOPS);
if (waited || buf_pool.try_LRU_scan)
{
/* If no block was in the free list, search from the end of the
LRU list and try to free a block there. If we are doing for the
first time we'll scan only tail of the LRU list otherwise we scan
the whole LRU list. */
if (buf_LRU_scan_and_free_block(waited ? ULINT_UNDEFINED : 100))
goto retry;
/* Tell other threads that there is no point in scanning the LRU
list. */
buf_pool.try_LRU_scan= false;
}
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-33613 InnoDB may still hang when temporarily running out of buffer pool By design, InnoDB has always hung when permanently running out of buffer pool, for example when several threads are waiting to allocate a block, and all of the buffer pool is buffer-fixed by the active threads. The hang that we are fixing here occurs when the buffer pool is only temporarily running out and the situation could be rescued by writing out some dirty pages or evicting some clean pages. buf_LRU_get_free_block(): Simplify the way how we wait for the buf_flush_page_cleaner thread. This fixes occasional hangs of the test encryption.innochecksum that were introduced by commit a55b951e6082a4ce9a1f2ed5ee176ea7dbbaf1f2 (MDEV-26827). To play it safe, we use a timed wait when waiting for the buf_flush_page_cleaner() thread to perform its job. Should that thread get stuck, we will invoke buf_pool.LRU_warn() in order to display a message that pages could not be freed, and keep trying to wake up the buf_flush_page_cleaner() thread. The INFORMATION_SCHEMA.INNODB_METRICS counters buffer_LRU_single_flush_failure_count and buffer_LRU_get_free_waits will be removed. The latter is represented by buffer_pool_wait_free. Also removed will be the message "InnoDB: Difficult to find free blocks in the buffer pool" because in d34479dc664d4cbd4e9dad6b0f92d7c8e55595d1 we introduced a more precise message "InnoDB: Could not free any blocks in the buffer pool" in the buf_flush_page_cleaner thread. buf_pool_t::LRU_warn(): Issue the warning message that we could not free any blocks in the buffer pool. This may also be invoked by buf_LRU_get_free_block() if buf_flush_page_cleaner() appears to be stuck. buf_pool_t::n_flush_dec(): Remove. buf_pool_t::n_flush_dec_holding_mutex(): Rename to n_flush_dec(). buf_flush_LRU_list_batch(): Increment the eviction counter for blocks of temporary, discarded or dropped tablespaces. buf_flush_LRU(): Make static, and remove the constant parameter evict=false. The only caller will be the buf_flush_page_cleaner() thread. IORequest::is_LRU(): Remove. The only case of evicting pages on write completion will be when we are writing out pages of the temporary tablespace. Those pages are not in buf_pool.flush_list, only in buf_pool.LRU. buf_page_t::flush(): Remove the parameter evict. buf_page_t::write_complete(): Change the parameter "bool temporary" to "bool persistent" and add a parameter for an already read state(). Reviewed by: Debarun Banerjee
2024-03-22 14:17:39 +02:00
waited= true;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-33613 InnoDB may still hang when temporarily running out of buffer pool By design, InnoDB has always hung when permanently running out of buffer pool, for example when several threads are waiting to allocate a block, and all of the buffer pool is buffer-fixed by the active threads. The hang that we are fixing here occurs when the buffer pool is only temporarily running out and the situation could be rescued by writing out some dirty pages or evicting some clean pages. buf_LRU_get_free_block(): Simplify the way how we wait for the buf_flush_page_cleaner thread. This fixes occasional hangs of the test encryption.innochecksum that were introduced by commit a55b951e6082a4ce9a1f2ed5ee176ea7dbbaf1f2 (MDEV-26827). To play it safe, we use a timed wait when waiting for the buf_flush_page_cleaner() thread to perform its job. Should that thread get stuck, we will invoke buf_pool.LRU_warn() in order to display a message that pages could not be freed, and keep trying to wake up the buf_flush_page_cleaner() thread. The INFORMATION_SCHEMA.INNODB_METRICS counters buffer_LRU_single_flush_failure_count and buffer_LRU_get_free_waits will be removed. The latter is represented by buffer_pool_wait_free. Also removed will be the message "InnoDB: Difficult to find free blocks in the buffer pool" because in d34479dc664d4cbd4e9dad6b0f92d7c8e55595d1 we introduced a more precise message "InnoDB: Could not free any blocks in the buffer pool" in the buf_flush_page_cleaner thread. buf_pool_t::LRU_warn(): Issue the warning message that we could not free any blocks in the buffer pool. This may also be invoked by buf_LRU_get_free_block() if buf_flush_page_cleaner() appears to be stuck. buf_pool_t::n_flush_dec(): Remove. buf_pool_t::n_flush_dec_holding_mutex(): Rename to n_flush_dec(). buf_flush_LRU_list_batch(): Increment the eviction counter for blocks of temporary, discarded or dropped tablespaces. buf_flush_LRU(): Make static, and remove the constant parameter evict=false. The only caller will be the buf_flush_page_cleaner() thread. IORequest::is_LRU(): Remove. The only case of evicting pages on write completion will be when we are writing out pages of the temporary tablespace. Those pages are not in buf_pool.flush_list, only in buf_pool.LRU. buf_page_t::flush(): Remove the parameter evict. buf_page_t::write_complete(): Change the parameter "bool temporary" to "bool persistent" and add a parameter for an already read state(). Reviewed by: Debarun Banerjee
2024-03-22 14:17:39 +02:00
while (!(block= buf_LRU_get_free_only()))
{
buf_pool.stat.LRU_waits++;
timespec abstime;
set_timespec(abstime, 1);
mysql_mutex_lock(&buf_pool.flush_list_mutex);
if (!buf_pool.page_cleaner_active())
buf_pool.page_cleaner_wakeup(true);
mysql_mutex_unlock(&buf_pool.flush_list_mutex);
if (my_cond_timedwait(&buf_pool.done_free, &buf_pool.mutex.m_mutex,
&abstime))
buf_pool.LRU_warn();
}
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-33613 InnoDB may still hang when temporarily running out of buffer pool By design, InnoDB has always hung when permanently running out of buffer pool, for example when several threads are waiting to allocate a block, and all of the buffer pool is buffer-fixed by the active threads. The hang that we are fixing here occurs when the buffer pool is only temporarily running out and the situation could be rescued by writing out some dirty pages or evicting some clean pages. buf_LRU_get_free_block(): Simplify the way how we wait for the buf_flush_page_cleaner thread. This fixes occasional hangs of the test encryption.innochecksum that were introduced by commit a55b951e6082a4ce9a1f2ed5ee176ea7dbbaf1f2 (MDEV-26827). To play it safe, we use a timed wait when waiting for the buf_flush_page_cleaner() thread to perform its job. Should that thread get stuck, we will invoke buf_pool.LRU_warn() in order to display a message that pages could not be freed, and keep trying to wake up the buf_flush_page_cleaner() thread. The INFORMATION_SCHEMA.INNODB_METRICS counters buffer_LRU_single_flush_failure_count and buffer_LRU_get_free_waits will be removed. The latter is represented by buffer_pool_wait_free. Also removed will be the message "InnoDB: Difficult to find free blocks in the buffer pool" because in d34479dc664d4cbd4e9dad6b0f92d7c8e55595d1 we introduced a more precise message "InnoDB: Could not free any blocks in the buffer pool" in the buf_flush_page_cleaner thread. buf_pool_t::LRU_warn(): Issue the warning message that we could not free any blocks in the buffer pool. This may also be invoked by buf_LRU_get_free_block() if buf_flush_page_cleaner() appears to be stuck. buf_pool_t::n_flush_dec(): Remove. buf_pool_t::n_flush_dec_holding_mutex(): Rename to n_flush_dec(). buf_flush_LRU_list_batch(): Increment the eviction counter for blocks of temporary, discarded or dropped tablespaces. buf_flush_LRU(): Make static, and remove the constant parameter evict=false. The only caller will be the buf_flush_page_cleaner() thread. IORequest::is_LRU(): Remove. The only case of evicting pages on write completion will be when we are writing out pages of the temporary tablespace. Those pages are not in buf_pool.flush_list, only in buf_pool.LRU. buf_page_t::flush(): Remove the parameter evict. buf_page_t::write_complete(): Change the parameter "bool temporary" to "bool persistent" and add a parameter for an already read state(). Reviewed by: Debarun Banerjee
2024-03-22 14:17:39 +02:00
goto got_block;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
/** Move the LRU_old pointer so that the length of the old blocks list
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
is inside the allowed limits. */
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
static void buf_LRU_old_adjust_len()
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
ulint old_len;
ulint new_len;
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
ut_a(buf_pool.LRU_old);
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_assert_owner(&buf_pool.mutex);
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
ut_ad(buf_pool.LRU_old_ratio >= BUF_LRU_OLD_RATIO_MIN);
ut_ad(buf_pool.LRU_old_ratio <= BUF_LRU_OLD_RATIO_MAX);
Use compile_time_assert() in InnoDB Replace most use of #error. Some checks were impossible to evaluate in the preprocessor due to the use of named integer constants or enumerations.
2018-04-30 15:46:09 +03:00
compile_time_assert(BUF_LRU_OLD_RATIO_MIN * BUF_LRU_OLD_MIN_LEN
> BUF_LRU_OLD_RATIO_DIV
* (BUF_LRU_OLD_TOLERANCE + 5));
compile_time_assert(BUF_LRU_NON_OLD_MIN_LEN < BUF_LRU_OLD_MIN_LEN);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
#ifdef UNIV_LRU_DEBUG
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
/* buf_pool.LRU_old must be the first item in the LRU list
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
whose "old" flag is set. */
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
ut_a(buf_pool.LRU_old->old);
ut_a(!UT_LIST_GET_PREV(LRU, buf_pool.LRU_old)
|| !UT_LIST_GET_PREV(LRU, buf_pool.LRU_old)->old);
ut_a(!UT_LIST_GET_NEXT(LRU, buf_pool.LRU_old)
|| UT_LIST_GET_NEXT(LRU, buf_pool.LRU_old)->old);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
#endif /* UNIV_LRU_DEBUG */
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
old_len = buf_pool.LRU_old_len;
new_len = ut_min(UT_LIST_GET_LEN(buf_pool.LRU)
* buf_pool.LRU_old_ratio / BUF_LRU_OLD_RATIO_DIV,
UT_LIST_GET_LEN(buf_pool.LRU)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
- (BUF_LRU_OLD_TOLERANCE
+ BUF_LRU_NON_OLD_MIN_LEN));
for (;;) {
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_page_t* LRU_old = buf_pool.LRU_old;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_a(LRU_old);
ut_ad(LRU_old->in_LRU_list);
#ifdef UNIV_LRU_DEBUG
ut_a(LRU_old->old);
#endif /* UNIV_LRU_DEBUG */
/* Update the LRU_old pointer if necessary */
if (old_len + BUF_LRU_OLD_TOLERANCE < new_len) {
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.LRU_old = LRU_old = UT_LIST_GET_PREV(
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
LRU, LRU_old);
#ifdef UNIV_LRU_DEBUG
ut_a(!LRU_old->old);
#endif /* UNIV_LRU_DEBUG */
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
old_len = ++buf_pool.LRU_old_len;
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
LRU_old->set_old(true);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
} else if (old_len > new_len + BUF_LRU_OLD_TOLERANCE) {
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.LRU_old = UT_LIST_GET_NEXT(LRU, LRU_old);
old_len = --buf_pool.LRU_old_len;
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
LRU_old->set_old(false);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
} else {
return;
}
}
}
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
/** Initialize the old blocks pointer in the LRU list. This function should be
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
called when the LRU list grows to BUF_LRU_OLD_MIN_LEN length. */
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
static void buf_LRU_old_init()
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_assert_owner(&buf_pool.mutex);
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
ut_a(UT_LIST_GET_LEN(buf_pool.LRU) == BUF_LRU_OLD_MIN_LEN);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* We first initialize all blocks in the LRU list as old and then use
the adjust function to move the LRU_old pointer to the right
position */
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
for (buf_page_t* bpage = UT_LIST_GET_LAST(buf_pool.LRU);
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
bpage != NULL;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
bpage = UT_LIST_GET_PREV(LRU, bpage)) {
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_ad(bpage->in_LRU_list);
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* This loop temporarily violates the
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
assertions of buf_page_t::set_old(). */
bpage->old = true;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.LRU_old = UT_LIST_GET_FIRST(buf_pool.LRU);
buf_pool.LRU_old_len = UT_LIST_GET_LEN(buf_pool.LRU);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_LRU_old_adjust_len();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
/** Remove a block from the unzip_LRU list if it belonged to the list.
@param[in] bpage control block */
static void buf_unzip_LRU_remove_block_if_needed(buf_page_t* bpage)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_ad(bpage->in_file());
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_assert_owner(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if (bpage->belongs_to_unzip_LRU()) {
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
buf_block_t* block = reinterpret_cast<buf_block_t*>(bpage);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_ad(block->in_unzip_LRU_list);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_d(block->in_unzip_LRU_list = false);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
UT_LIST_REMOVE(buf_pool.unzip_LRU, block);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
}
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
/** Removes a block from the LRU list.
@param[in] bpage control block */
static inline void buf_LRU_remove_block(buf_page_t* bpage)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-6936: Buffer pool list scan optimization Merged Facebook commit 617aef9f911d825e9053f3d611d0389e02031225 authored by Inaam Rana to InnoDB storage engine (not XtraDB) from https://github.com/facebook/mysql-5.6 WL#7047 - Optimize buffer pool list scans and related batch processing Reduce excessive scanning of pages when doing flush list batches. The fix is to introduce the concept of "Hazard Pointer", this reduces the time complexity of the scan from O(n*n) to O. The concept of hazard pointer is reversed in this work. Academically hazard pointer is a pointer that the thread working on it will declar such and as long as that thread is not done no other thread is allowe do anything with it. In this WL we declare the pointer as a hazard pointer and then if any thread attempts to work on it, it is allowed to do so but it has to a the hazard pointer to the next valid value. We use hazard pointer sol reverse traversal of lists within a buffer pool instance. Add an event to control the background flush thread. The background f thread wait has been converted to an os event timed wait so that it c signalled by threads that want to kick start a background flush when buffer pool is running low on free/dirty pages.
2014-11-06 13:17:11 +02:00
/* Important that we adjust the hazard pointers before removing
bpage from the LRU list. */
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
buf_page_t* prev_bpage = buf_pool.LRU_remove(bpage);
MDEV-6936: Buffer pool list scan optimization Merged Facebook commit 617aef9f911d825e9053f3d611d0389e02031225 authored by Inaam Rana to InnoDB storage engine (not XtraDB) from https://github.com/facebook/mysql-5.6 WL#7047 - Optimize buffer pool list scans and related batch processing Reduce excessive scanning of pages when doing flush list batches. The fix is to introduce the concept of "Hazard Pointer", this reduces the time complexity of the scan from O(n*n) to O. The concept of hazard pointer is reversed in this work. Academically hazard pointer is a pointer that the thread working on it will declar such and as long as that thread is not done no other thread is allowe do anything with it. In this WL we declare the pointer as a hazard pointer and then if any thread attempts to work on it, it is allowed to do so but it has to a the hazard pointer to the next valid value. We use hazard pointer sol reverse traversal of lists within a buffer pool instance. Add an event to control the background flush thread. The background f thread wait has been converted to an os event timed wait so that it c signalled by threads that want to kick start a background flush when buffer pool is running low on free/dirty pages.
2014-11-06 13:17:11 +02:00
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* If the LRU_old pointer is defined and points to just this block,
move it backward one step */
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
if (bpage == buf_pool.LRU_old) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* Below: the previous block is guaranteed to exist,
because the LRU_old pointer is only allowed to differ
by BUF_LRU_OLD_TOLERANCE from strict
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.LRU_old_ratio/BUF_LRU_OLD_RATIO_DIV of the LRU
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
list length. */
ut_a(prev_bpage);
#ifdef UNIV_LRU_DEBUG
ut_a(!prev_bpage->old);
#endif /* UNIV_LRU_DEBUG */
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.LRU_old = prev_bpage;
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
prev_bpage->set_old(true);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.LRU_old_len++;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.stat.LRU_bytes -= bpage->physical_size();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
buf_unzip_LRU_remove_block_if_needed(bpage);
/* If the LRU list is so short that LRU_old is not defined,
clear the "old" flags and return */
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
if (UT_LIST_GET_LEN(buf_pool.LRU) < BUF_LRU_OLD_MIN_LEN) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
for (buf_page_t* bpage = UT_LIST_GET_FIRST(buf_pool.LRU);
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
bpage != NULL;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
bpage = UT_LIST_GET_NEXT(LRU, bpage)) {
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* This loop temporarily violates the
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
assertions of buf_page_t::set_old(). */
bpage->old = false;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.LRU_old = NULL;
buf_pool.LRU_old_len = 0;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
return;
}
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
ut_ad(buf_pool.LRU_old);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* Update the LRU_old_len field if necessary */
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if (bpage->old) {
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.LRU_old_len--;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
/* Adjust the length of the old block list if necessary */
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_LRU_old_adjust_len();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
/******************************************************************//**
Adds a block to the LRU list of decompressed zip pages. */
void
buf_unzip_LRU_add_block(
/*====================*/
buf_block_t* block, /*!< in: control block */
ibool old) /*!< in: TRUE if should be put to the end
of the list, else put to the start */
{
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_assert_owner(&buf_pool.mutex);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_a(block->page.belongs_to_unzip_LRU());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_ad(!block->in_unzip_LRU_list);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_d(block->in_unzip_LRU_list = true);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
if (old) {
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
UT_LIST_ADD_LAST(buf_pool.unzip_LRU, block);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
} else {
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
UT_LIST_ADD_FIRST(buf_pool.unzip_LRU, block);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
}
/******************************************************************//**
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
Adds a block to the LRU list. Please make sure that the page_size is
already set when invoking the function, so that we can get correct
page_size from the buffer page when adding a block into LRU */
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
void
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
buf_LRU_add_block(
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
buf_page_t* bpage, /*!< in: control block */
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
bool old) /*!< in: true if should be put to the old blocks
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
in the LRU list, else put to the start; if the
LRU list is very short, the block is added to
the start, regardless of this parameter */
{
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_assert_owner(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_ad(!bpage->in_LRU_list);
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
if (!old || (UT_LIST_GET_LEN(buf_pool.LRU) < BUF_LRU_OLD_MIN_LEN)) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
UT_LIST_ADD_FIRST(buf_pool.LRU, bpage);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
bpage->freed_page_clock = buf_pool.freed_page_clock
MDEV-21907: InnoDB: Enable -Wconversion on clang and GCC The -Wconversion in GCC seems to be stricter than in clang. GCC at least since version 4.4.7 issues truncation warnings for assignments to bitfields, while clang 10 appears to only issue warnings when the sizes in bytes rounded to the nearest integer powers of 2 are different. Before GCC 10.0.0, -Wconversion required more casts and would not allow some operations, such as x<<=1 or x+=1 on a data type that is narrower than int. GCC 5 (but not GCC 4, GCC 6, or any later version) is complaining about x|=y even when x and y are compatible types that are narrower than int. Hence, we must rewrite some x|=y as x=static_cast<byte>(x|y) or similar, or we must disable -Wconversion. In GCC 6 and later, the warning for assigning wider to bitfields that are narrower than 8, 16, or 32 bits can be suppressed by applying a bitwise & with the exact bitmask of the bitfield. For older GCC, we must disable -Wconversion for GCC 4 or 5 in such cases. The bitwise negation operator appears to promote short integers to a wider type, and hence we must add explicit truncation casts around them. Microsoft Visual C does not allow a static_cast to truncate a constant, such as static_cast<byte>(1) truncating int. Hence, we will use the constructor-style cast byte(~1) for such cases. This has been tested at least with GCC 4.8.5, 5.4.0, 7.4.0, 9.2.1, 10.0.0, clang 9.0.1, 10.0.0, and MSVC 14.22.27905 (Microsoft Visual Studio 2019) on 64-bit and 32-bit targets (IA-32, AMD64, POWER 8, POWER 9, ARMv8).
2020-03-12 19:46:41 +02:00
& ((1U << 31) - 1);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
} else {
#ifdef UNIV_LRU_DEBUG
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
/* buf_pool.LRU_old must be the first item in the LRU list
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
whose "old" flag is set. */
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
ut_a(buf_pool.LRU_old->old);
ut_a(!UT_LIST_GET_PREV(LRU, buf_pool.LRU_old)
|| !UT_LIST_GET_PREV(LRU, buf_pool.LRU_old)->old);
ut_a(!UT_LIST_GET_NEXT(LRU, buf_pool.LRU_old)
|| UT_LIST_GET_NEXT(LRU, buf_pool.LRU_old)->old);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
#endif /* UNIV_LRU_DEBUG */
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
UT_LIST_INSERT_AFTER(buf_pool.LRU, buf_pool.LRU_old,
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
bpage);
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.LRU_old_len++;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
ut_d(bpage->in_LRU_list = TRUE);
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
incr_LRU_size_in_bytes(bpage);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
if (UT_LIST_GET_LEN(buf_pool.LRU) > BUF_LRU_OLD_MIN_LEN) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
ut_ad(buf_pool.LRU_old);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* Adjust the length of the old block list if necessary */
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
bpage->set_old(old);
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_LRU_old_adjust_len();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
} else if (UT_LIST_GET_LEN(buf_pool.LRU) == BUF_LRU_OLD_MIN_LEN) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* The LRU list is now long enough for LRU_old to become
defined: init it */
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_LRU_old_init();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
} else {
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
bpage->set_old(buf_pool.LRU_old != NULL);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
/* If this is a zipped block with decompressed frame as well
then put it on the unzip_LRU list */
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if (bpage->belongs_to_unzip_LRU()) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
buf_unzip_LRU_add_block((buf_block_t*) bpage, old);
}
}
MDEV-15053 follow-up to reduce buf_pool.mutex contention buf_LRU_make_block_young(): Merge with buf_page_make_young(). buf_pool_check_no_pending_io(): Remove. Replaced with buf_pool.any_io_pending() and buf_pool.io_pending(), which do not unnecessarily acquire buf_pool.mutex. buf_pool_t::init_flush[]: Use atomic access, so that buf_flush_wait_LRU_batch_end() can avoid acquiring buf_pool.mutex. buf_pool_t::try_LRU_scan: Declare as bool.
2020-06-08 13:14:27 +03:00
/** Move a block to the start of the LRU list. */
void buf_page_make_young(buf_page_t *bpage)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
if (bpage->is_read_fixed())
return;
MDEV-15053 follow-up to reduce buf_pool.mutex contention buf_LRU_make_block_young(): Merge with buf_page_make_young(). buf_pool_check_no_pending_io(): Remove. Replaced with buf_pool.any_io_pending() and buf_pool.io_pending(), which do not unnecessarily acquire buf_pool.mutex. buf_pool_t::init_flush[]: Use atomic access, so that buf_flush_wait_LRU_batch_end() can avoid acquiring buf_pool.mutex. buf_pool_t::try_LRU_scan: Declare as bool.
2020-06-08 13:14:27 +03:00
ut_ad(bpage->in_file());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_lock(&buf_pool.mutex);
MDEV-15053 follow-up to reduce buf_pool.mutex contention buf_LRU_make_block_young(): Merge with buf_page_make_young(). buf_pool_check_no_pending_io(): Remove. Replaced with buf_pool.any_io_pending() and buf_pool.io_pending(), which do not unnecessarily acquire buf_pool.mutex. buf_pool_t::init_flush[]: Use atomic access, so that buf_flush_wait_LRU_batch_end() can avoid acquiring buf_pool.mutex. buf_pool_t::try_LRU_scan: Declare as bool.
2020-06-08 13:14:27 +03:00
if (UNIV_UNLIKELY(bpage->old))
buf_pool.stat.n_pages_made_young++;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15053 follow-up to reduce buf_pool.mutex contention buf_LRU_make_block_young(): Merge with buf_page_make_young(). buf_pool_check_no_pending_io(): Remove. Replaced with buf_pool.any_io_pending() and buf_pool.io_pending(), which do not unnecessarily acquire buf_pool.mutex. buf_pool_t::init_flush[]: Use atomic access, so that buf_flush_wait_LRU_batch_end() can avoid acquiring buf_pool.mutex. buf_pool_t::try_LRU_scan: Declare as bool.
2020-06-08 13:14:27 +03:00
buf_LRU_remove_block(bpage);
buf_LRU_add_block(bpage, false);
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_unlock(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-32068 Some calls to buf_read_ahead_linear() seem to be useless The linear read-ahead (enabled by nonzero innodb_read_ahead_threshold) works best if index leaf pages or undo log pages have been allocated on adjacent page numbers. The read-ahead is assumed not to be helpful in other types of page accesses, such as non-leaf index pages. buf_page_get_low(): Do not invoke buf_page_t::set_accessed(), buf_page_make_young_if_needed(), or buf_read_ahead_linear(). We will invoke them in those callers of buf_page_get_gen() or buf_page_get() where it makes sense: the access is not one-time-on-startup and the page and not going to be freed soon. btr_copy_blob_prefix(), btr_pcur_move_to_next_page(), trx_undo_get_prev_rec_from_prev_page(), trx_undo_get_first_rec(), btr_cur_t::search_leaf(), btr_cur_t::open_leaf(): Invoke buf_read_ahead_linear(). We will not invoke linear read-ahead in functions that would essentially allocate or free pages, because pages that are freshly allocated are expected to be initialized by buf_page_create() and not read from the data file. Likewise, freeing pages should not involve accessing any sibling pages, except for freeing singly-linked lists of BLOB pages. We will not invoke read-ahead in btr_cur_t::pessimistic_search_leaf() or in a pessimistic operation of btr_cur_t::open_leaf(), because it is assumed that pessimistic operations should be preceded by optimistic operations, which should already have invoked read-ahead. buf_page_make_young_if_needed(): Invoke also buf_page_t::set_accessed() and return the result. btr_cur_nonleaf_make_young(): Like buf_page_make_young_if_needed(), but do not invoke buf_page_t::set_accessed(). Reviewed by: Vladislav Lesin Tested by: Matthias Leich
2023-12-05 12:31:29 +02:00
bool buf_page_make_young_if_needed(buf_page_t *bpage)
{
const bool not_first{bpage->set_accessed()};
if (UNIV_UNLIKELY(buf_page_peek_if_too_old(bpage)))
buf_page_make_young(bpage);
return not_first;
}
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
/** Try to free a block. If bpage is a descriptor of a compressed-only
ROW_FORMAT=COMPRESSED page, the buf_page_t object will be freed as well.
The caller must hold buf_pool.mutex.
@param bpage block to be freed
@param zip whether to remove both copies of a ROW_FORMAT=COMPRESSED page
@retval true if freed and buf_pool.mutex may have been temporarily released
@retval false if the page was not freed */
bool buf_LRU_free_page(buf_page_t *bpage, bool zip)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
const page_id_t id{bpage->id()};
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
buf_page_t* b = nullptr;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_assert_owner(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-22850 Reduce buf_pool.page_hash latch contention For reads, the buf_pool.page_hash is protected by buf_pool.mutex or by the hash_lock. There is no need to compute or acquire hash_lock if we are not modifying the buf_pool.page_hash. However, the buf_pool.page_hash latch must be held exclusively when changing buf_page_t::in_file(), or if we desire to prevent buf_page_t::can_relocate() or buf_page_t::buf_fix_count() from changing. rw_lock_lock_word_decr(): Add a comment that explains the polling logic. buf_page_t::set_state(): When in_file() is to be changed, assert that an exclusive buf_pool.page_hash latch is being held. Unfortunately we cannot assert this for set_state(BUF_BLOCK_REMOVE_HASH) because set_corrupt_id() may already have been called. buf_LRU_free_page(): Check buf_page_t::can_relocate() before aqcuiring the hash_lock. buf_block_t::initialise(): Initialize also page.buf_fix_count(). buf_page_create(): Initialize buf_fix_count while not holding any mutex or hash_lock. Acquire the hash_lock only for the duration of inserting the block to the buf_pool.page_hash. buf_LRU_old_init(), buf_LRU_add_block(), buf_page_t::belongs_to_unzip_LRU(): Do not assert buf_page_t::in_file(), because buf_page_create() will invoke buf_LRU_add_block() before acquiring hash_lock and buf_page_t::set_state(). buf_pool_t::validate(): Rely on the buf_pool.mutex and do not unnecessarily acquire any buf_pool.page_hash latches. buf_page_init_for_read(): Clarify that we must acquire the hash_lock upfront in order to prevent a race with buf_pool_t::watch_remove().
2020-06-11 17:30:33 +03:00
/* First, perform a quick check before we acquire hash_lock. */
if (!bpage->can_relocate()) {
return false;
}
/* We must hold an exclusive hash_lock to prevent
bpage->can_relocate() from changing due to a concurrent
execution of buf_page_get_low(). */
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
buf_pool_t::hash_chain& chain= buf_pool.page_hash.cell_get(id.fold());
page_hash_latch& hash_lock = buf_pool.page_hash.lock_get(chain);
MDEV-26769 InnoDB does not support hardware lock elision This implements memory transaction support for: * Intel Restricted Transactional Memory (RTM), also known as TSX-NI (Transactional Synchronization Extensions New Instructions) * POWER v2.09 Hardware Trace Monitor (HTM) on GNU/Linux transactional_lock_guard, transactional_shared_lock_guard: RAII lock guards that try to elide the lock acquisition when transactional memory is available. buf_pool.page_hash: Try to elide latches whenever feasible. Related to the InnoDB change buffer and ROW_FORMAT=COMPRESSED tables, this is not always possible. In buf_page_get_low(), memory transactions only work reasonably well for validating a guessed block address. TMLockGuard, TMLockTrxGuard, TMLockMutexGuard: RAII lock guards that try to elide lock_sys.latch and related latches.
2021-10-22 12:38:45 +03:00
/* We cannot use transactional_lock_guard here,
because buf_buddy_relocate() in buf_buddy_free() could get stuck. */
hash_lock.lock();
MDEV-26055: Improve adaptive flushing Adaptive flushing is enabled by setting innodb_max_dirty_pages_pct_lwm>0 (not default) and innodb_adaptive_flushing=ON (default). There is also the parameter innodb_adaptive_flushing_lwm (default: 10 per cent of the log capacity). It should enable some adaptive flushing even when innodb_max_dirty_pages_pct_lwm=0. That is not being changed here. This idea was first presented by Inaam Rana several years ago, and I discussed it with Jean-François Gagné at FOSDEM 2023. buf_flush_page_cleaner(): When we are not near the log capacity limit (neither buf_flush_async_lsn nor buf_flush_sync_lsn are set), also try to move clean blocks from the buf_pool.LRU list to buf_pool.free or initiate writes (but not the eviction) of dirty blocks, until the remaining I/O capacity has been consumed. buf_flush_LRU_list_batch(): Add the parameter bool evict, to specify whether dirty least recently used pages (from buf_pool.LRU) should be evicted immediately after they have been written out. Callers outside buf_flush_page_cleaner() will pass evict=true, to retain the existing behaviour. buf_do_LRU_batch(): Add the parameter bool evict. Return counts of evicted and flushed pages. buf_flush_LRU(): Add the parameter bool evict. Assume that the caller holds buf_pool.mutex and will invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_list_holding_mutex(): A low-level variant of buf_flush_list() whose caller must hold buf_pool.mutex and invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_wait_batch_end_acquiring_mutex(): Remove. It is enough to have buf_flush_wait_batch_end(). page_cleaner_flush_pages_recommendation(): Avoid some floating-point arithmetics. buf_flush_page(), buf_flush_check_neighbor(), buf_flush_check_neighbors(), buf_flush_try_neighbors(): Rename the parameter "bool lru" to "bool evict". buf_free_from_unzip_LRU_list_batch(): Remove the parameter. Only actual page writes will contribute towards the limit. buf_LRU_free_page(): Evict freed pages of temporary tables. buf_pool.done_free: Broadcast whenever a block is freed (and buf_pool.try_LRU_scan is set). buf_pool_t::io_buf_t::reserve(): Retry indefinitely. During the test encryption.innochecksum we easily run out of these buffers for PAGE_COMPRESSED or ENCRYPTED pages. Tested by Matthias Leich and Axel Schwenke
2023-03-16 17:09:08 +02:00
const lsn_t oldest_modification = bpage->oldest_modification_acquire();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-22850 Reduce buf_pool.page_hash latch contention For reads, the buf_pool.page_hash is protected by buf_pool.mutex or by the hash_lock. There is no need to compute or acquire hash_lock if we are not modifying the buf_pool.page_hash. However, the buf_pool.page_hash latch must be held exclusively when changing buf_page_t::in_file(), or if we desire to prevent buf_page_t::can_relocate() or buf_page_t::buf_fix_count() from changing. rw_lock_lock_word_decr(): Add a comment that explains the polling logic. buf_page_t::set_state(): When in_file() is to be changed, assert that an exclusive buf_pool.page_hash latch is being held. Unfortunately we cannot assert this for set_state(BUF_BLOCK_REMOVE_HASH) because set_corrupt_id() may already have been called. buf_LRU_free_page(): Check buf_page_t::can_relocate() before aqcuiring the hash_lock. buf_block_t::initialise(): Initialize also page.buf_fix_count(). buf_page_create(): Initialize buf_fix_count while not holding any mutex or hash_lock. Acquire the hash_lock only for the duration of inserting the block to the buf_pool.page_hash. buf_LRU_old_init(), buf_LRU_add_block(), buf_page_t::belongs_to_unzip_LRU(): Do not assert buf_page_t::in_file(), because buf_page_create() will invoke buf_LRU_add_block() before acquiring hash_lock and buf_page_t::set_state(). buf_pool_t::validate(): Rely on the buf_pool.mutex and do not unnecessarily acquire any buf_pool.page_hash latches. buf_page_init_for_read(): Clarify that we must acquire the hash_lock upfront in order to prevent a race with buf_pool_t::watch_remove().
2020-06-11 17:30:33 +03:00
if (UNIV_UNLIKELY(!bpage->can_relocate())) {
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
/* Do not free buffer fixed and I/O-fixed blocks. */
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
goto func_exit;
}
MDEV-26055: Improve adaptive flushing Adaptive flushing is enabled by setting innodb_max_dirty_pages_pct_lwm>0 (not default) and innodb_adaptive_flushing=ON (default). There is also the parameter innodb_adaptive_flushing_lwm (default: 10 per cent of the log capacity). It should enable some adaptive flushing even when innodb_max_dirty_pages_pct_lwm=0. That is not being changed here. This idea was first presented by Inaam Rana several years ago, and I discussed it with Jean-François Gagné at FOSDEM 2023. buf_flush_page_cleaner(): When we are not near the log capacity limit (neither buf_flush_async_lsn nor buf_flush_sync_lsn are set), also try to move clean blocks from the buf_pool.LRU list to buf_pool.free or initiate writes (but not the eviction) of dirty blocks, until the remaining I/O capacity has been consumed. buf_flush_LRU_list_batch(): Add the parameter bool evict, to specify whether dirty least recently used pages (from buf_pool.LRU) should be evicted immediately after they have been written out. Callers outside buf_flush_page_cleaner() will pass evict=true, to retain the existing behaviour. buf_do_LRU_batch(): Add the parameter bool evict. Return counts of evicted and flushed pages. buf_flush_LRU(): Add the parameter bool evict. Assume that the caller holds buf_pool.mutex and will invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_list_holding_mutex(): A low-level variant of buf_flush_list() whose caller must hold buf_pool.mutex and invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_wait_batch_end_acquiring_mutex(): Remove. It is enough to have buf_flush_wait_batch_end(). page_cleaner_flush_pages_recommendation(): Avoid some floating-point arithmetics. buf_flush_page(), buf_flush_check_neighbor(), buf_flush_check_neighbors(), buf_flush_try_neighbors(): Rename the parameter "bool lru" to "bool evict". buf_free_from_unzip_LRU_list_batch(): Remove the parameter. Only actual page writes will contribute towards the limit. buf_LRU_free_page(): Evict freed pages of temporary tables. buf_pool.done_free: Broadcast whenever a block is freed (and buf_pool.try_LRU_scan is set). buf_pool_t::io_buf_t::reserve(): Retry indefinitely. During the test encryption.innochecksum we easily run out of these buffers for PAGE_COMPRESSED or ENCRYPTED pages. Tested by Matthias Leich and Axel Schwenke
2023-03-16 17:09:08 +02:00
switch (oldest_modification) {
case 2:
ut_ad(id.space() == SRV_TMP_SPACE_ID);
ut_ad(!bpage->zip.data);
if (!bpage->is_freed()) {
goto func_exit;
}
bpage->clear_oldest_modification();
break;
case 1:
MDEV-25113: Make page flushing faster buf_page_write_complete(): Reduce the buf_pool.mutex hold time, and do not acquire buf_pool.flush_list_mutex at all. Instead, mark blocks clean by setting oldest_modification to 1. Dirty pages of temporary tables will be identified by the special value 2 instead of the previous special value 1. (By design of the ib_logfile0 format, actual LSN values smaller than 2048 are not possible.) buf_LRU_free_page(), buf_pool_t::get_oldest_modification() and many other functions will remove the garbage (clean blocks) from buf_pool.flush_list while holding buf_pool.flush_list_mutex. buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaced with non-atomic variables, protected by buf_pool.mutex, to avoid unnecessary synchronization when modifying the counts. export_vars: Remove unnecessary indirection for innodb_pages_created, innodb_pages_read, innodb_pages_written.
2021-06-23 13:13:11 +03:00
mysql_mutex_lock(&buf_pool.flush_list_mutex);
MDEV-26055: Improve adaptive flushing Adaptive flushing is enabled by setting innodb_max_dirty_pages_pct_lwm>0 (not default) and innodb_adaptive_flushing=ON (default). There is also the parameter innodb_adaptive_flushing_lwm (default: 10 per cent of the log capacity). It should enable some adaptive flushing even when innodb_max_dirty_pages_pct_lwm=0. That is not being changed here. This idea was first presented by Inaam Rana several years ago, and I discussed it with Jean-François Gagné at FOSDEM 2023. buf_flush_page_cleaner(): When we are not near the log capacity limit (neither buf_flush_async_lsn nor buf_flush_sync_lsn are set), also try to move clean blocks from the buf_pool.LRU list to buf_pool.free or initiate writes (but not the eviction) of dirty blocks, until the remaining I/O capacity has been consumed. buf_flush_LRU_list_batch(): Add the parameter bool evict, to specify whether dirty least recently used pages (from buf_pool.LRU) should be evicted immediately after they have been written out. Callers outside buf_flush_page_cleaner() will pass evict=true, to retain the existing behaviour. buf_do_LRU_batch(): Add the parameter bool evict. Return counts of evicted and flushed pages. buf_flush_LRU(): Add the parameter bool evict. Assume that the caller holds buf_pool.mutex and will invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_list_holding_mutex(): A low-level variant of buf_flush_list() whose caller must hold buf_pool.mutex and invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_wait_batch_end_acquiring_mutex(): Remove. It is enough to have buf_flush_wait_batch_end(). page_cleaner_flush_pages_recommendation(): Avoid some floating-point arithmetics. buf_flush_page(), buf_flush_check_neighbor(), buf_flush_check_neighbors(), buf_flush_try_neighbors(): Rename the parameter "bool lru" to "bool evict". buf_free_from_unzip_LRU_list_batch(): Remove the parameter. Only actual page writes will contribute towards the limit. buf_LRU_free_page(): Evict freed pages of temporary tables. buf_pool.done_free: Broadcast whenever a block is freed (and buf_pool.try_LRU_scan is set). buf_pool_t::io_buf_t::reserve(): Retry indefinitely. During the test encryption.innochecksum we easily run out of these buffers for PAGE_COMPRESSED or ENCRYPTED pages. Tested by Matthias Leich and Axel Schwenke
2023-03-16 17:09:08 +02:00
if (const lsn_t om = bpage->oldest_modification()) {
ut_ad(om == 1);
MDEV-25113: Make page flushing faster buf_page_write_complete(): Reduce the buf_pool.mutex hold time, and do not acquire buf_pool.flush_list_mutex at all. Instead, mark blocks clean by setting oldest_modification to 1. Dirty pages of temporary tables will be identified by the special value 2 instead of the previous special value 1. (By design of the ib_logfile0 format, actual LSN values smaller than 2048 are not possible.) buf_LRU_free_page(), buf_pool_t::get_oldest_modification() and many other functions will remove the garbage (clean blocks) from buf_pool.flush_list while holding buf_pool.flush_list_mutex. buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaced with non-atomic variables, protected by buf_pool.mutex, to avoid unnecessary synchronization when modifying the counts. export_vars: Remove unnecessary indirection for innodb_pages_created, innodb_pages_read, innodb_pages_written.
2021-06-23 13:13:11 +03:00
buf_pool.delete_from_flush_list(bpage);
}
mysql_mutex_unlock(&buf_pool.flush_list_mutex);
ut_ad(!bpage->oldest_modification());
MDEV-26055: Improve adaptive flushing Adaptive flushing is enabled by setting innodb_max_dirty_pages_pct_lwm>0 (not default) and innodb_adaptive_flushing=ON (default). There is also the parameter innodb_adaptive_flushing_lwm (default: 10 per cent of the log capacity). It should enable some adaptive flushing even when innodb_max_dirty_pages_pct_lwm=0. That is not being changed here. This idea was first presented by Inaam Rana several years ago, and I discussed it with Jean-François Gagné at FOSDEM 2023. buf_flush_page_cleaner(): When we are not near the log capacity limit (neither buf_flush_async_lsn nor buf_flush_sync_lsn are set), also try to move clean blocks from the buf_pool.LRU list to buf_pool.free or initiate writes (but not the eviction) of dirty blocks, until the remaining I/O capacity has been consumed. buf_flush_LRU_list_batch(): Add the parameter bool evict, to specify whether dirty least recently used pages (from buf_pool.LRU) should be evicted immediately after they have been written out. Callers outside buf_flush_page_cleaner() will pass evict=true, to retain the existing behaviour. buf_do_LRU_batch(): Add the parameter bool evict. Return counts of evicted and flushed pages. buf_flush_LRU(): Add the parameter bool evict. Assume that the caller holds buf_pool.mutex and will invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_list_holding_mutex(): A low-level variant of buf_flush_list() whose caller must hold buf_pool.mutex and invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_wait_batch_end_acquiring_mutex(): Remove. It is enough to have buf_flush_wait_batch_end(). page_cleaner_flush_pages_recommendation(): Avoid some floating-point arithmetics. buf_flush_page(), buf_flush_check_neighbor(), buf_flush_check_neighbors(), buf_flush_try_neighbors(): Rename the parameter "bool lru" to "bool evict". buf_free_from_unzip_LRU_list_batch(): Remove the parameter. Only actual page writes will contribute towards the limit. buf_LRU_free_page(): Evict freed pages of temporary tables. buf_pool.done_free: Broadcast whenever a block is freed (and buf_pool.try_LRU_scan is set). buf_pool_t::io_buf_t::reserve(): Retry indefinitely. During the test encryption.innochecksum we easily run out of these buffers for PAGE_COMPRESSED or ENCRYPTED pages. Tested by Matthias Leich and Axel Schwenke
2023-03-16 17:09:08 +02:00
/* fall through */
case 0:
if (zip || !bpage->zip.data || !bpage->frame) {
break;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-26055: Improve adaptive flushing Adaptive flushing is enabled by setting innodb_max_dirty_pages_pct_lwm>0 (not default) and innodb_adaptive_flushing=ON (default). There is also the parameter innodb_adaptive_flushing_lwm (default: 10 per cent of the log capacity). It should enable some adaptive flushing even when innodb_max_dirty_pages_pct_lwm=0. That is not being changed here. This idea was first presented by Inaam Rana several years ago, and I discussed it with Jean-François Gagné at FOSDEM 2023. buf_flush_page_cleaner(): When we are not near the log capacity limit (neither buf_flush_async_lsn nor buf_flush_sync_lsn are set), also try to move clean blocks from the buf_pool.LRU list to buf_pool.free or initiate writes (but not the eviction) of dirty blocks, until the remaining I/O capacity has been consumed. buf_flush_LRU_list_batch(): Add the parameter bool evict, to specify whether dirty least recently used pages (from buf_pool.LRU) should be evicted immediately after they have been written out. Callers outside buf_flush_page_cleaner() will pass evict=true, to retain the existing behaviour. buf_do_LRU_batch(): Add the parameter bool evict. Return counts of evicted and flushed pages. buf_flush_LRU(): Add the parameter bool evict. Assume that the caller holds buf_pool.mutex and will invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_list_holding_mutex(): A low-level variant of buf_flush_list() whose caller must hold buf_pool.mutex and invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_wait_batch_end_acquiring_mutex(): Remove. It is enough to have buf_flush_wait_batch_end(). page_cleaner_flush_pages_recommendation(): Avoid some floating-point arithmetics. buf_flush_page(), buf_flush_check_neighbor(), buf_flush_check_neighbors(), buf_flush_try_neighbors(): Rename the parameter "bool lru" to "bool evict". buf_free_from_unzip_LRU_list_batch(): Remove the parameter. Only actual page writes will contribute towards the limit. buf_LRU_free_page(): Evict freed pages of temporary tables. buf_pool.done_free: Broadcast whenever a block is freed (and buf_pool.try_LRU_scan is set). buf_pool_t::io_buf_t::reserve(): Retry indefinitely. During the test encryption.innochecksum we easily run out of these buffers for PAGE_COMPRESSED or ENCRYPTED pages. Tested by Matthias Leich and Axel Schwenke
2023-03-16 17:09:08 +02:00
relocate_compressed:
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
b = static_cast<buf_page_t*>(ut_zalloc_nokey(sizeof *b));
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_a(b);
MDEV-26200 buf_pool.flush_list corrupted by buffer pool resizing or ROW_FORMAT=COMPRESSED The lazy deletion of clean blocks from buf_pool.flush_list that was introduced in commit 6441bc614a99f5cd6357c8a23b9f583c56d0a90c (MDEV-25113) introduced a race condition around the function buf_flush_relocate_on_flush_list(). The test innodb_zip.wl5522_debug_zip as well as the buffer pool resizing tests would occasionally fail in debug builds due to buf_pool.flush_list.count disagreeing with the actual length of the doubly-linked list. The safe procedure for relocating a block in buf_pool.flush_list should be as follows, now that we implement lazy deletion from buf_pool.flush_list: 1. Acquire buf_pool.mutex. 2. Acquire the exclusive buf_pool.page_hash.latch. 3. Acquire buf_pool.flush_list_mutex. 4. Copy the block descriptor. 5. Invoke buf_flush_relocate_on_flush_list(). 6. Release buf_pool.flush_list_mutex. buf_flush_relocate_on_flush_list(): Assert that buf_pool.flush_list_mutex is being held. Invoke buf_page_t::oldest_modification() only once, using std::memory_order_relaxed, now that the mutex protects us. buf_LRU_free_page(), buf_LRU_block_remove_hashed(): Avoid an unlock-lock cycle on hash_lock. (We must not acquire hash_lock while already holding buf_pool.flush_list_mutex, because that could lead to a deadlock due to latching order violation.)
2021-07-22 08:34:49 +03:00
mysql_mutex_lock(&buf_pool.flush_list_mutex);
Fix -Wclass-memaccess warnings in InnoDB,XtraDB
2018-08-03 11:22:20 +03:00
new (b) buf_page_t(*bpage);
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
b->frame = nullptr;
MDEV-31816 buf_LRU_free_page() does not preserve ROW_FORMAT=COMPRESSED block state buf_LRU_free_page(): When we are discarding the uncompressed copy of a ROW_FORMAT=COMPRESSED page, buf_page_t::can_relocate() must have ensured that the block descriptor state is one of FREED, UNFIXED, REINIT. Do not overwrite the state with UNFIXED. We do not want to write back pages that were actually freed, and we want to avoid doublewrite for pages that were (re)initialized by log records written since the latest checkpoint. Last but not least, we do not want crashes like those that commit dc1bd1802a3175e2b890df368482cd39b5ed9444 (MDEV-31386) was supposed to fix. The test innodb_zip.wl5522_zip should typically cover all 3 states. This bug is a regression due to commit aaef2e1d8c843d1e40b1ce0c5199c3abb3c5da28 (MDEV-27058).
2023-08-01 09:58:15 +03:00
{
ut_d(uint32_t s=) b->fix();
ut_ad(s == buf_page_t::FREED
|| s == buf_page_t::UNFIXED
MDEV-31816 fixup: Relax a debug assertion buf_LRU_free_page(): The block may also be in the IBUF_EXIST state when executing the test innodb.innodb_bulk_create_index_debug.
2023-08-01 13:22:16 +03:00
|| s == buf_page_t::IBUF_EXIST
MDEV-31816 buf_LRU_free_page() does not preserve ROW_FORMAT=COMPRESSED block state buf_LRU_free_page(): When we are discarding the uncompressed copy of a ROW_FORMAT=COMPRESSED page, buf_page_t::can_relocate() must have ensured that the block descriptor state is one of FREED, UNFIXED, REINIT. Do not overwrite the state with UNFIXED. We do not want to write back pages that were actually freed, and we want to avoid doublewrite for pages that were (re)initialized by log records written since the latest checkpoint. Last but not least, we do not want crashes like those that commit dc1bd1802a3175e2b890df368482cd39b5ed9444 (MDEV-31386) was supposed to fix. The test innodb_zip.wl5522_zip should typically cover all 3 states. This bug is a regression due to commit aaef2e1d8c843d1e40b1ce0c5199c3abb3c5da28 (MDEV-27058).
2023-08-01 09:58:15 +03:00
|| s == buf_page_t::REINIT);
}
MDEV-26055: Improve adaptive flushing Adaptive flushing is enabled by setting innodb_max_dirty_pages_pct_lwm>0 (not default) and innodb_adaptive_flushing=ON (default). There is also the parameter innodb_adaptive_flushing_lwm (default: 10 per cent of the log capacity). It should enable some adaptive flushing even when innodb_max_dirty_pages_pct_lwm=0. That is not being changed here. This idea was first presented by Inaam Rana several years ago, and I discussed it with Jean-François Gagné at FOSDEM 2023. buf_flush_page_cleaner(): When we are not near the log capacity limit (neither buf_flush_async_lsn nor buf_flush_sync_lsn are set), also try to move clean blocks from the buf_pool.LRU list to buf_pool.free or initiate writes (but not the eviction) of dirty blocks, until the remaining I/O capacity has been consumed. buf_flush_LRU_list_batch(): Add the parameter bool evict, to specify whether dirty least recently used pages (from buf_pool.LRU) should be evicted immediately after they have been written out. Callers outside buf_flush_page_cleaner() will pass evict=true, to retain the existing behaviour. buf_do_LRU_batch(): Add the parameter bool evict. Return counts of evicted and flushed pages. buf_flush_LRU(): Add the parameter bool evict. Assume that the caller holds buf_pool.mutex and will invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_list_holding_mutex(): A low-level variant of buf_flush_list() whose caller must hold buf_pool.mutex and invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_wait_batch_end_acquiring_mutex(): Remove. It is enough to have buf_flush_wait_batch_end(). page_cleaner_flush_pages_recommendation(): Avoid some floating-point arithmetics. buf_flush_page(), buf_flush_check_neighbor(), buf_flush_check_neighbors(), buf_flush_try_neighbors(): Rename the parameter "bool lru" to "bool evict". buf_free_from_unzip_LRU_list_batch(): Remove the parameter. Only actual page writes will contribute towards the limit. buf_LRU_free_page(): Evict freed pages of temporary tables. buf_pool.done_free: Broadcast whenever a block is freed (and buf_pool.try_LRU_scan is set). buf_pool_t::io_buf_t::reserve(): Retry indefinitely. During the test encryption.innochecksum we easily run out of these buffers for PAGE_COMPRESSED or ENCRYPTED pages. Tested by Matthias Leich and Axel Schwenke
2023-03-16 17:09:08 +02:00
break;
default:
if (zip || !bpage->zip.data || !bpage->frame) {
/* This would completely free the block. */
/* Do not completely free dirty blocks. */
func_exit:
hash_lock.unlock();
return(false);
}
goto relocate_compressed;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_assert_owner(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-26055: Improve adaptive flushing Adaptive flushing is enabled by setting innodb_max_dirty_pages_pct_lwm>0 (not default) and innodb_adaptive_flushing=ON (default). There is also the parameter innodb_adaptive_flushing_lwm (default: 10 per cent of the log capacity). It should enable some adaptive flushing even when innodb_max_dirty_pages_pct_lwm=0. That is not being changed here. This idea was first presented by Inaam Rana several years ago, and I discussed it with Jean-François Gagné at FOSDEM 2023. buf_flush_page_cleaner(): When we are not near the log capacity limit (neither buf_flush_async_lsn nor buf_flush_sync_lsn are set), also try to move clean blocks from the buf_pool.LRU list to buf_pool.free or initiate writes (but not the eviction) of dirty blocks, until the remaining I/O capacity has been consumed. buf_flush_LRU_list_batch(): Add the parameter bool evict, to specify whether dirty least recently used pages (from buf_pool.LRU) should be evicted immediately after they have been written out. Callers outside buf_flush_page_cleaner() will pass evict=true, to retain the existing behaviour. buf_do_LRU_batch(): Add the parameter bool evict. Return counts of evicted and flushed pages. buf_flush_LRU(): Add the parameter bool evict. Assume that the caller holds buf_pool.mutex and will invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_list_holding_mutex(): A low-level variant of buf_flush_list() whose caller must hold buf_pool.mutex and invoke buf_dblwr.flush_buffered_writes() afterwards. buf_flush_wait_batch_end_acquiring_mutex(): Remove. It is enough to have buf_flush_wait_batch_end(). page_cleaner_flush_pages_recommendation(): Avoid some floating-point arithmetics. buf_flush_page(), buf_flush_check_neighbor(), buf_flush_check_neighbors(), buf_flush_try_neighbors(): Rename the parameter "bool lru" to "bool evict". buf_free_from_unzip_LRU_list_batch(): Remove the parameter. Only actual page writes will contribute towards the limit. buf_LRU_free_page(): Evict freed pages of temporary tables. buf_pool.done_free: Broadcast whenever a block is freed (and buf_pool.try_LRU_scan is set). buf_pool_t::io_buf_t::reserve(): Retry indefinitely. During the test encryption.innochecksum we easily run out of these buffers for PAGE_COMPRESSED or ENCRYPTED pages. Tested by Matthias Leich and Axel Schwenke
2023-03-16 17:09:08 +02:00
DBUG_PRINT("ib_buf", ("free page %u:%u", id.space(), id.page_no()));
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_ad(bpage->can_relocate());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
if (!buf_LRU_block_remove_hashed(bpage, id, chain, zip)) {
MDEV-26200 buf_pool.flush_list corrupted by buffer pool resizing or ROW_FORMAT=COMPRESSED The lazy deletion of clean blocks from buf_pool.flush_list that was introduced in commit 6441bc614a99f5cd6357c8a23b9f583c56d0a90c (MDEV-25113) introduced a race condition around the function buf_flush_relocate_on_flush_list(). The test innodb_zip.wl5522_debug_zip as well as the buffer pool resizing tests would occasionally fail in debug builds due to buf_pool.flush_list.count disagreeing with the actual length of the doubly-linked list. The safe procedure for relocating a block in buf_pool.flush_list should be as follows, now that we implement lazy deletion from buf_pool.flush_list: 1. Acquire buf_pool.mutex. 2. Acquire the exclusive buf_pool.page_hash.latch. 3. Acquire buf_pool.flush_list_mutex. 4. Copy the block descriptor. 5. Invoke buf_flush_relocate_on_flush_list(). 6. Release buf_pool.flush_list_mutex. buf_flush_relocate_on_flush_list(): Assert that buf_pool.flush_list_mutex is being held. Invoke buf_page_t::oldest_modification() only once, using std::memory_order_relaxed, now that the mutex protects us. buf_LRU_free_page(), buf_LRU_block_remove_hashed(): Avoid an unlock-lock cycle on hash_lock. (We must not acquire hash_lock while already holding buf_pool.flush_list_mutex, because that could lead to a deadlock due to latching order violation.)
2021-07-22 08:34:49 +03:00
ut_ad(!b);
mysql_mutex_assert_not_owner(&buf_pool.flush_list_mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
return(true);
}
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
/* We have just freed a BUF_BLOCK_FILE_PAGE. If b != nullptr
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
then it was a compressed page with an uncompressed frame and
we are interested in freeing only the uncompressed frame.
Therefore we have to reinsert the compressed page descriptor
into the LRU and page_hash (and possibly flush_list).
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if !b then it was a regular page that has been freed */
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if (UNIV_LIKELY_NULL(b)) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
buf_page_t* prev_b = UT_LIST_GET_PREV(LRU, b);
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
ut_ad(!buf_pool.page_hash.get(id, chain));
MDEV-18493 Remove page_size_t MySQL 5.7 introduced the class page_size_t and increased the size of buffer pool page descriptors by introducing this object to them. Maybe the intention of this exercise was to prepare for a future where the buffer pool could accommodate multiple page sizes. But that future never arrived, not even in MySQL 8.0. It is much easier to manage a pool of a single page size, and typically all storage devices of an InnoDB instance benefit from using the same page size. Let us remove page_size_t from MariaDB Server. This will make it easier to remove support for ROW_FORMAT=COMPRESSED (or make it a compile-time option) in the future, just by removing various occurrences of zip_size.
2019-02-06 19:50:11 +02:00
ut_ad(b->zip_size());
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
/* The field in_LRU_list of
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
the to-be-freed block descriptor should have
been cleared in
buf_LRU_block_remove_hashed(), which
invokes buf_LRU_remove_block(). */
ut_ad(!bpage->in_LRU_list);
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
ut_ad(bpage->frame);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_ad(!((buf_block_t*) bpage)->in_unzip_LRU_list);
/* The fields of bpage were copied to b before
buf_LRU_block_remove_hashed() was invoked. */
ut_ad(!b->in_zip_hash);
ut_ad(b->in_LRU_list);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_ad(b->in_page_hash);
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
ut_d(b->in_page_hash = false);
b->hash = nullptr;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
buf_pool.page_hash.append(chain, b);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* Insert b where bpage was in the LRU list. */
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if (prev_b) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ulint lru_len;
ut_ad(prev_b->in_LRU_list);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_ad(prev_b->in_file());
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
UT_LIST_INSERT_AFTER(buf_pool.LRU, prev_b, b);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
incr_LRU_size_in_bytes(b);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if (b->is_old()) {
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.LRU_old_len++;
if (buf_pool.LRU_old
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
== UT_LIST_GET_NEXT(LRU, b)) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.LRU_old = b;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
}
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
lru_len = UT_LIST_GET_LEN(buf_pool.LRU);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
if (lru_len > BUF_LRU_OLD_MIN_LEN) {
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
ut_ad(buf_pool.LRU_old);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* Adjust the length of the
old block list if necessary */
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_LRU_old_adjust_len();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
} else if (lru_len == BUF_LRU_OLD_MIN_LEN) {
/* The LRU list is now long
enough for LRU_old to become
defined: init it */
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_LRU_old_init();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
#ifdef UNIV_LRU_DEBUG
/* Check that the "old" flag is consistent
in the block and its neighbours. */
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
b->set_old(b->is_old());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
#endif /* UNIV_LRU_DEBUG */
} else {
ut_d(b->in_LRU_list = FALSE);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
buf_LRU_add_block(b, b->old);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
buf_flush_relocate_on_flush_list(bpage, b);
MDEV-26200 buf_pool.flush_list corrupted by buffer pool resizing or ROW_FORMAT=COMPRESSED The lazy deletion of clean blocks from buf_pool.flush_list that was introduced in commit 6441bc614a99f5cd6357c8a23b9f583c56d0a90c (MDEV-25113) introduced a race condition around the function buf_flush_relocate_on_flush_list(). The test innodb_zip.wl5522_debug_zip as well as the buffer pool resizing tests would occasionally fail in debug builds due to buf_pool.flush_list.count disagreeing with the actual length of the doubly-linked list. The safe procedure for relocating a block in buf_pool.flush_list should be as follows, now that we implement lazy deletion from buf_pool.flush_list: 1. Acquire buf_pool.mutex. 2. Acquire the exclusive buf_pool.page_hash.latch. 3. Acquire buf_pool.flush_list_mutex. 4. Copy the block descriptor. 5. Invoke buf_flush_relocate_on_flush_list(). 6. Release buf_pool.flush_list_mutex. buf_flush_relocate_on_flush_list(): Assert that buf_pool.flush_list_mutex is being held. Invoke buf_page_t::oldest_modification() only once, using std::memory_order_relaxed, now that the mutex protects us. buf_LRU_free_page(), buf_LRU_block_remove_hashed(): Avoid an unlock-lock cycle on hash_lock. (We must not acquire hash_lock while already holding buf_pool.flush_list_mutex, because that could lead to a deadlock due to latching order violation.)
2021-07-22 08:34:49 +03:00
mysql_mutex_unlock(&buf_pool.flush_list_mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
bpage->zip.data = nullptr;
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
page_zip_set_size(&bpage->zip, 0);
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
b->lock.x_lock();
hash_lock.unlock();
MDEV-26200 buf_pool.flush_list corrupted by buffer pool resizing or ROW_FORMAT=COMPRESSED The lazy deletion of clean blocks from buf_pool.flush_list that was introduced in commit 6441bc614a99f5cd6357c8a23b9f583c56d0a90c (MDEV-25113) introduced a race condition around the function buf_flush_relocate_on_flush_list(). The test innodb_zip.wl5522_debug_zip as well as the buffer pool resizing tests would occasionally fail in debug builds due to buf_pool.flush_list.count disagreeing with the actual length of the doubly-linked list. The safe procedure for relocating a block in buf_pool.flush_list should be as follows, now that we implement lazy deletion from buf_pool.flush_list: 1. Acquire buf_pool.mutex. 2. Acquire the exclusive buf_pool.page_hash.latch. 3. Acquire buf_pool.flush_list_mutex. 4. Copy the block descriptor. 5. Invoke buf_flush_relocate_on_flush_list(). 6. Release buf_pool.flush_list_mutex. buf_flush_relocate_on_flush_list(): Assert that buf_pool.flush_list_mutex is being held. Invoke buf_page_t::oldest_modification() only once, using std::memory_order_relaxed, now that the mutex protects us. buf_LRU_free_page(), buf_LRU_block_remove_hashed(): Avoid an unlock-lock cycle on hash_lock. (We must not acquire hash_lock while already holding buf_pool.flush_list_mutex, because that could lead to a deadlock due to latching order violation.)
2021-07-22 08:34:49 +03:00
} else if (!zip) {
MDEV-26769 InnoDB does not support hardware lock elision This implements memory transaction support for: * Intel Restricted Transactional Memory (RTM), also known as TSX-NI (Transactional Synchronization Extensions New Instructions) * POWER v2.09 Hardware Trace Monitor (HTM) on GNU/Linux transactional_lock_guard, transactional_shared_lock_guard: RAII lock guards that try to elide the lock acquisition when transactional memory is available. buf_pool.page_hash: Try to elide latches whenever feasible. Related to the InnoDB change buffer and ROW_FORMAT=COMPRESSED tables, this is not always possible. In buf_page_get_low(), memory transactions only work reasonably well for validating a guessed block address. TMLockGuard, TMLockTrxGuard, TMLockMutexGuard: RAII lock guards that try to elide lock_sys.latch and related latches.
2021-10-22 12:38:45 +03:00
hash_lock.unlock();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-20377: Make WITH_MSAN more usable MemorySanitizer (clang -fsanitize=memory) requires that all code be compiled with instrumentation enabled. The only exception is the C runtime library. Failure to use instrumented libraries will cause bogus messages about memory being uninitialized. In WITH_MSAN builds, we must avoid calling getservbyname(), because even though it is a standard library function, it is not instrumented, not even in clang 10. Note: Before MariaDB Server 10.5, ./mtr will typically fail due to the old PCRE library, which was updated in MDEV-14024. The following cmake options were tested on 10.5 in commit 94d0bb4dbeb28a94d1f87fdd55f4297ff3df0157: cmake \ -DCMAKE_C_FLAGS='-march=native -O2' \ -DCMAKE_CXX_FLAGS='-stdlib=libc++ -march=native -O2' \ -DWITH_EMBEDDED_SERVER=OFF -DWITH_UNIT_TESTS=OFF -DCMAKE_BUILD_TYPE=Debug \ -DWITH_INNODB_{BZIP2,LZ4,LZMA,LZO,SNAPPY}=OFF \ -DPLUGIN_{ARCHIVE,TOKUDB,MROONGA,OQGRAPH,ROCKSDB,CONNECT,SPIDER}=NO \ -DWITH_SAFEMALLOC=OFF \ -DWITH_{ZLIB,SSL,PCRE}=bundled \ -DHAVE_LIBAIO_H=0 \ -DWITH_MSAN=ON MEM_MAKE_DEFINED(): An alias for VALGRIND_MAKE_MEM_DEFINED() and __msan_unpoison(). MEM_GET_VBITS(), MEM_SET_VBITS(): Aliases for VALGRIND_GET_VBITS(), VALGRIND_SET_VBITS(), __msan_copy_shadow(). InnoDB: Replace the UNIV_MEM_ macros with corresponding MEM_ macros. ut_crc32_8_hw(), ut_crc32_64_low_hw(): Use the compiler built-in functions instead of inline assembler when building WITH_MSAN. This will require at least -msse4.2 when building for IA-32 or AMD64. The inline assembler would not be instrumented, and would thus cause bogus failures.
2020-07-01 17:23:00 +03:00
buf_block_t* block = reinterpret_cast<buf_block_t*>(bpage);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
#ifdef BTR_CUR_HASH_ADAPT
if (block->index) {
mysql_mutex_unlock(&buf_pool.mutex);
/* Remove the adaptive hash index on the page.
The page was declared uninitialized by
buf_LRU_block_remove_hashed(). We need to flag
the contents of the page valid (which it still is) in
order to avoid bogus Valgrind or MSAN warnings.*/
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
MEM_MAKE_DEFINED(block->page.frame, srv_page_size);
Merge 10.4 into 10.5
2022-12-13 14:39:18 +02:00
btr_search_drop_page_hash_index(block, false);
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
MEM_UNDEFINED(block->page.frame, srv_page_size);
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_lock(&buf_pool.mutex);
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
}
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
#endif
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if (UNIV_LIKELY_NULL(b)) {
ut_ad(b->zip_size());
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
b->lock.x_unlock();
b->unfix();
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
}
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-20377: Make WITH_MSAN more usable MemorySanitizer (clang -fsanitize=memory) requires that all code be compiled with instrumentation enabled. The only exception is the C runtime library. Failure to use instrumented libraries will cause bogus messages about memory being uninitialized. In WITH_MSAN builds, we must avoid calling getservbyname(), because even though it is a standard library function, it is not instrumented, not even in clang 10. Note: Before MariaDB Server 10.5, ./mtr will typically fail due to the old PCRE library, which was updated in MDEV-14024. The following cmake options were tested on 10.5 in commit 94d0bb4dbeb28a94d1f87fdd55f4297ff3df0157: cmake \ -DCMAKE_C_FLAGS='-march=native -O2' \ -DCMAKE_CXX_FLAGS='-stdlib=libc++ -march=native -O2' \ -DWITH_EMBEDDED_SERVER=OFF -DWITH_UNIT_TESTS=OFF -DCMAKE_BUILD_TYPE=Debug \ -DWITH_INNODB_{BZIP2,LZ4,LZMA,LZO,SNAPPY}=OFF \ -DPLUGIN_{ARCHIVE,TOKUDB,MROONGA,OQGRAPH,ROCKSDB,CONNECT,SPIDER}=NO \ -DWITH_SAFEMALLOC=OFF \ -DWITH_{ZLIB,SSL,PCRE}=bundled \ -DHAVE_LIBAIO_H=0 \ -DWITH_MSAN=ON MEM_MAKE_DEFINED(): An alias for VALGRIND_MAKE_MEM_DEFINED() and __msan_unpoison(). MEM_GET_VBITS(), MEM_SET_VBITS(): Aliases for VALGRIND_GET_VBITS(), VALGRIND_SET_VBITS(), __msan_copy_shadow(). InnoDB: Replace the UNIV_MEM_ macros with corresponding MEM_ macros. ut_crc32_8_hw(), ut_crc32_64_low_hw(): Use the compiler built-in functions instead of inline assembler when building WITH_MSAN. This will require at least -msse4.2 when building for IA-32 or AMD64. The inline assembler would not be instrumented, and would thus cause bogus failures.
2020-07-01 17:23:00 +03:00
buf_LRU_block_free_hashed_page(block);
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
return(true);
}
/******************************************************************//**
Puts a block back to the free list. */
void
buf_LRU_block_free_non_file_page(
/*=============================*/
buf_block_t* block) /*!< in: block, must not contain a file page */
{
void* data;
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
ut_ad(block->page.state() == buf_page_t::MEMORY);
Bug#24346574 PAGE CLEANER THREAD, ASSERT BLOCK->N_POINTERS == 0 btr_search_drop_page_hash_index(): Do not return before ensuring that block->index=NULL, even if !btr_search_enabled. We would typically still skip acquiring the AHI latch when the AHI is disabled, because block->index would already be NULL. Only if the AHI is in the process of being disabled, we would wait for the AHI latch and then notice that block->index=NULL and return. The above bug was a regression caused in MySQL 5.7.9 by the fix of Bug#21407023: DISABLING AHI SHOULD AVOID TAKING AHI LATCH The rest of this patch improves diagnostics by adding assertions. assert_block_ahi_valid(): A debug predicate for checking that block->n_pointers!=0 implies block->index!=NULL. assert_block_ahi_empty(): A debug predicate for checking that block->n_pointers==0. buf_block_init(): Instead of assigning block->n_pointers=0, assert_block_ahi_empty(block). buf_pool_clear_hash_index(): Clarify comments, and assign block->n_pointers=0 before assigning block->index=NULL. The wrong ordering could make block->n_pointers appear incorrect in debug assertions. This bug was introduced in MySQL 5.1.52 by Bug#13006367 62487: INNODB TAKES 3 MINUTES TO CLEAN UP THE ADAPTIVE HASH INDEX AT SHUTDOWN i_s_innodb_buffer_page_get_info(): Add a comment that the IS_HASHED column in the INFORMATION_SCHEMA views INNODB_BUFFER_POOL_PAGE and INNODB_BUFFER_PAGE_LRU may show false positives (there may be no pointers after all.) ha_insert_for_fold_func(), ha_delete_hash_node(), ha_search_and_update_if_found_func(): Use atomics for updating buf_block_t::n_pointers. While buf_block_t::index is always protected by btr_search_x_lock(index), in ha_insert_for_fold_func() the n_pointers-- may belong to another dict_index_t whose btr_search_latches[] we are not holding. RB: 13879 Reviewed-by: Jimmy Yang <jimmy.yang@oracle.com>
2016-09-02 17:28:54 +03:00
assert_block_ahi_empty(block);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_ad(!block->page.in_free_list);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_ad(!block->page.oldest_modification());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_ad(!block->page.in_LRU_list);
MDEV-26826 fixup: ROW_FORMAT=COMPRESSED may corrupt buf_pool.page_hash In commit c091a0bc8da87045f10bfc96618ed7194768fa2d we removed the use of the HASH_ macros for inserting into buf_pool.page_hash, or accessing buf_page_t::hash. However, the binary buddy allocator for block->page.zip.data would still use the HASH_ macros. HASH_INSERT and not HASH_DELETE would reset the next-block pointer to the null pointer. Our replacement of HASH_DELETE() will reset the next-block pointer, and the replacement of HASH_INSERT() assumes that the pointer is the null pointer. buf_LRU_block_free_non_file_page(): Assert that the next-block pointer is the null pointer. buf_buddy_block_free(): Reset the pointer before invoking buf_LRU_block_free_non_file_page(). Without this, the added assertion would fail in the test encryption.innochecksum.
2021-11-05 08:09:33 +02:00
ut_ad(!block->page.hash);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
block->page.set_state(buf_page_t::NOT_USED);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
MEM_UNDEFINED(block->page.frame, srv_page_size);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
data = block->page.zip.data;
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
if (data != NULL) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
block->page.zip.data = NULL;
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_pool_mutex_exit_forbid();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-18493 Remove page_size_t MySQL 5.7 introduced the class page_size_t and increased the size of buffer pool page descriptors by introducing this object to them. Maybe the intention of this exercise was to prepare for a future where the buffer pool could accommodate multiple page sizes. But that future never arrived, not even in MySQL 8.0. It is much easier to manage a pool of a single page size, and typically all storage devices of an InnoDB instance benefit from using the same page size. Let us remove page_size_t from MariaDB Server. This will make it easier to remove support for ROW_FORMAT=COMPRESSED (or make it a compile-time option) in the future, just by removing various occurrences of zip_size.
2019-02-06 19:50:11 +02:00
ut_ad(block->zip_size());
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_buddy_free(data, block->zip_size());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_pool_mutex_exit_allow();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
page_zip_set_size(&block->page.zip, 0);
}
MDEV-27891: SIGSEGV in InnoDB buffer pool resize During an increase in resize, the new curr_size got a value less than old_size. As n_chunks_new and n_chunks have a strong correlation to the resizing operation in progress, we can use them and remove the need for old_size. For convienece the n_chunks_new < n_chunks is now the is_shrinking function. The volatile compiler optimization on n_chunks{,_new} is removed as real mutex uses are needed. Other n_chunks_new/n_chunks methods: n_chunks_new and n_chunks almost always read and altered under the pool mutex. Exceptions are: * i_s_innodb_buffer_page_fill, * buf_pool_t::is_uncompressed (via is_blocked_field) These need reexamining for the need of a mutex, however comments indicates this already. get_n_pages has uses in buffer pool load, recover log memory exhaustion estimates and innodb status so take the minimum number of chunks for safety. The buf_pool_t::running_out function also uses curr_size/old_size. We replace this hot function calculation with just n_chunks_new. This is the new size of the chunks before the resizing occurs. If we are resizing down, we've already got the case we had previously (as the minimum). If we are resizing upwards, we are taking an optimistic view that there will be buffer chunks available for locks. As this memory allocation is occurring immediately next the resizing function it seems likely. Compiler hint UNIV_UNLIKELY removed to leave it to the branch predictor to make an informed decision. Added test case of a smaller size than the Marko/Roel original in JIRA reducing the size to 256M. SEGV hits roughly 1/10 times but its better than a 21G memory size. Reviewer: Marko
2022-02-22 17:42:59 +11:00
if (buf_pool.is_shrinking()
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
&& UT_LIST_GET_LEN(buf_pool.withdraw) < buf_pool.withdraw_target
&& buf_pool.will_be_withdrawn(block->page)) {
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
/* This should be withdrawn */
UT_LIST_ADD_LAST(
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.withdraw,
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
&block->page);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_d(block->in_withdraw_list = true);
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
} else {
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
UT_LIST_ADD_FIRST(buf_pool.free, &block->page);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_d(block->page.in_free_list = true);
MDEV-26827 Make page flushing even faster For more convenient monitoring of something that could greatly affect the volume of page writes, we add the status variable Innodb_buffer_pool_pages_split that was previously only available via information_schema.innodb_metrics as "innodb_page_splits". This was suggested by Axel Schwenke. buf_flush_page_count: Replaced with buf_pool.stat.n_pages_written. We protect buf_pool.stat (except n_page_gets) with buf_pool.mutex and remove unnecessary export_vars indirection. buf_pool.flush_list_bytes: Moved from buf_pool.stat.flush_list_bytes. Protected by buf_pool.flush_list_mutex. buf_pool_t::page_cleaner_status: Replaces buf_pool_t::n_flush_LRU_, buf_pool_t::n_flush_list_, and buf_pool_t::page_cleaner_is_idle. Protected by buf_pool.flush_list_mutex. We will exclusively broadcast buf_pool.done_flush_list by the buf_flush_page_cleaner thread, and only wait for it when communicating with buf_flush_page_cleaner. There is no need to keep a count of pending writes by the buf_pool.flush_list processing. A single flag suffices for that. Waits for page write completion can be performed by simply waiting on block->page.lock, or by invoking buf_dblwr.wait_for_page_writes(). buf_LRU_block_free_non_file_page(): Broadcast buf_pool.done_free and set buf_pool.try_LRU_scan when freeing a page. This would be executed also as part of buf_page_write_complete(). buf_page_write_complete(): Do not broadcast buf_pool.done_flush_list, and do not acquire buf_pool.mutex unless buf_pool.LRU eviction is needed. Let buf_dblwr count all writes to persistent pages and broadcast a condition variable when no outstanding writes remain. buf_flush_page_cleaner(): Prioritize LRU flushing and eviction right after "furious flushing" (lsn_limit). Simplify the conditions and reduce the hold time of buf_pool.flush_list_mutex. Refuse to shut down or sleep if buf_pool.ran_out(), that is, LRU eviction is needed. buf_pool_t::page_cleaner_wakeup(): Add the optional parameter for_LRU. buf_LRU_get_free_block(): Protect buf_lru_free_blocks_error_printed with buf_pool.mutex. Invoke buf_pool.page_cleaner_wakeup(true) to to ensure that buf_flush_page_cleaner() will process the LRU flush request. buf_do_LRU_batch(), buf_flush_list(), buf_flush_list_space(): Update buf_pool.stat.n_pages_written when submitting writes (while holding buf_pool.mutex), not when completing them. buf_page_t::flush(), buf_flush_discard_page(): Require that the page U-latch be acquired upfront, and remove buf_page_t::ready_for_flush(). buf_pool_t::delete_from_flush_list(): Remove the parameter "bool clear". buf_flush_page(): Count pending page writes via buf_dblwr. buf_flush_try_neighbors(): Take the block of page_id as a parameter. If the tablespace is dropped before our page has been written out, release the page U-latch. buf_pool_invalidate(): Let the caller ensure that there are no outstanding writes. buf_flush_wait_batch_end(false), buf_flush_wait_batch_end_acquiring_mutex(false): Replaced with buf_dblwr.wait_for_page_writes(). buf_flush_wait_LRU_batch_end(): Replaces buf_flush_wait_batch_end(true). buf_flush_list(): Remove some broadcast of buf_pool.done_flush_list. buf_flush_buffer_pool(): Invoke also buf_dblwr.wait_for_page_writes(). buf_pool_t::io_pending(), buf_pool_t::n_flush_list(): Remove. Outstanding writes are reflected by buf_dblwr.pending_writes(). buf_dblwr_t::init(): New function, to initialize the mutex and the condition variables, but not the backing store. buf_dblwr_t::is_created(): Replaces buf_dblwr_t::is_initialised(). buf_dblwr_t::pending_writes(), buf_dblwr_t::writes_pending: Keeps track of writes of persistent data pages. buf_flush_LRU(): Allow calls while LRU flushing may be in progress in another thread. Tested by Matthias Leich (correctness) and Axel Schwenke (performance)
2023-03-16 17:19:58 +02:00
buf_pool.try_LRU_scan= true;
pthread_cond_broadcast(&buf_pool.done_free);
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
}
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-25341: innodb buffer pool soft decommit of memory When InnoDB isn't using memory its polite to other system processes to allow that memory to be used. Create buf_page_t::set_os_unused, to madvise(MADV_FREE)/ DiscardVirtualMemory innodb buffer pool pages to keep virtual mapping but allow kernel to reclaim memory. set_os_unused is called by buf_LRU_block_free_non_file_page for flushing deallocations to free up memory. set_os_used is called by buf_block_t::initialise (used by buf_page_create_low and buf_LRU_get_free_only. Move MSan (memory sanitizer) directive to be associated with set_os_{un,}used so that the correctness can be determined by instrumentation and test cases rather than relying on OS behaviour at specific times. Remove existing page information poisoning in buf_LRU_block_free_non_file_page. Tested by: Matthias Leich Reviewer: Marko Mäkelä Windows Review: Vladislav Vaintroub
2022-08-12 19:03:12 +10:00
block->page.set_os_unused();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
/** Release a memory block to the buffer pool. */
ATTRIBUTE_COLD void buf_pool_t::free_block(buf_block_t *block)
{
ut_ad(this == &buf_pool);
mysql_mutex_lock(&mutex);
buf_LRU_block_free_non_file_page(block);
mysql_mutex_unlock(&mutex);
}
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
/** Remove bpage from buf_pool.LRU and buf_pool.page_hash.
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
If !bpage->frame && !bpage->oldest_modification(), the object will be freed.
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
@param bpage buffer block
@param id page identifier
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
@param chain locked buf_pool.page_hash chain (will be released here)
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
@param zip whether bpage->zip of BUF_BLOCK_FILE_PAGE should be freed
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
If a compressed page is freed other compressed pages may be relocated.
@retval true if BUF_BLOCK_FILE_PAGE was removed from page_hash. The
caller needs to free the page to the free list
@retval false if BUF_BLOCK_ZIP_PAGE was removed from page_hash. In
this case the block is already returned to the buddy allocator. */
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
static bool buf_LRU_block_remove_hashed(buf_page_t *bpage, const page_id_t id,
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
buf_pool_t::hash_chain &chain,
bool zip)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
ut_a(bpage->can_relocate());
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
ut_ad(buf_pool.page_hash.lock_get(chain).is_write_locked());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
buf_LRU_remove_block(bpage);
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.freed_page_clock += 1;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
Clean up buf_LRU_remove_hashed() buf_LRU_block_remove_hashed(): Test for "not ROW_FORMAT=COMPRESSED" first, because in that case we can assume that an uncompressed page exists. This removes a condition from the likely code branch.
2023-08-25 13:44:59 +03:00
if (UNIV_LIKELY(!bpage->zip.data)) {
MDEV-20377: Make WITH_MSAN more usable MemorySanitizer (clang -fsanitize=memory) requires that all code be compiled with instrumentation enabled. The only exception is the C runtime library. Failure to use instrumented libraries will cause bogus messages about memory being uninitialized. In WITH_MSAN builds, we must avoid calling getservbyname(), because even though it is a standard library function, it is not instrumented, not even in clang 10. Note: Before MariaDB Server 10.5, ./mtr will typically fail due to the old PCRE library, which was updated in MDEV-14024. The following cmake options were tested on 10.5 in commit 94d0bb4dbeb28a94d1f87fdd55f4297ff3df0157: cmake \ -DCMAKE_C_FLAGS='-march=native -O2' \ -DCMAKE_CXX_FLAGS='-stdlib=libc++ -march=native -O2' \ -DWITH_EMBEDDED_SERVER=OFF -DWITH_UNIT_TESTS=OFF -DCMAKE_BUILD_TYPE=Debug \ -DWITH_INNODB_{BZIP2,LZ4,LZMA,LZO,SNAPPY}=OFF \ -DPLUGIN_{ARCHIVE,TOKUDB,MROONGA,OQGRAPH,ROCKSDB,CONNECT,SPIDER}=NO \ -DWITH_SAFEMALLOC=OFF \ -DWITH_{ZLIB,SSL,PCRE}=bundled \ -DHAVE_LIBAIO_H=0 \ -DWITH_MSAN=ON MEM_MAKE_DEFINED(): An alias for VALGRIND_MAKE_MEM_DEFINED() and __msan_unpoison(). MEM_GET_VBITS(), MEM_SET_VBITS(): Aliases for VALGRIND_GET_VBITS(), VALGRIND_SET_VBITS(), __msan_copy_shadow(). InnoDB: Replace the UNIV_MEM_ macros with corresponding MEM_ macros. ut_crc32_8_hw(), ut_crc32_64_low_hw(): Use the compiler built-in functions instead of inline assembler when building WITH_MSAN. This will require at least -msse4.2 when building for IA-32 or AMD64. The inline assembler would not be instrumented, and would thus cause bogus failures.
2020-07-01 17:23:00 +03:00
MEM_CHECK_ADDRESSABLE(bpage, sizeof(buf_block_t));
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
MEM_CHECK_ADDRESSABLE(bpage->frame, srv_page_size);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
buf_block_modify_clock_inc((buf_block_t*) bpage);
Clean up buf_LRU_remove_hashed() buf_LRU_block_remove_hashed(): Test for "not ROW_FORMAT=COMPRESSED" first, because in that case we can assume that an uncompressed page exists. This removes a condition from the likely code branch.
2023-08-25 13:44:59 +03:00
} else if (const page_t *page = bpage->frame) {
MEM_CHECK_ADDRESSABLE(bpage, sizeof(buf_block_t));
MEM_CHECK_ADDRESSABLE(bpage->frame, srv_page_size);
buf_block_modify_clock_inc((buf_block_t*) bpage);
ut_a(!zip || !bpage->oldest_modification());
ut_ad(bpage->zip_size());
/* Skip consistency checks if the page was freed.
In recovery, we could get a sole FREE_PAGE record
and nothing else, for a ROW_FORMAT=COMPRESSED page.
Its contents would be garbage. */
if (!bpage->is_freed())
switch (fil_page_get_type(page)) {
case FIL_PAGE_TYPE_ALLOCATED:
case FIL_PAGE_INODE:
case FIL_PAGE_IBUF_BITMAP:
case FIL_PAGE_TYPE_FSP_HDR:
case FIL_PAGE_TYPE_XDES:
/* These are essentially uncompressed pages. */
if (!zip) {
/* InnoDB writes the data to the
uncompressed page frame. Copy it
to the compressed page, which will
be preserved. */
memcpy(bpage->zip.data, page,
bpage->zip_size());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
Clean up buf_LRU_remove_hashed() buf_LRU_block_remove_hashed(): Test for "not ROW_FORMAT=COMPRESSED" first, because in that case we can assume that an uncompressed page exists. This removes a condition from the likely code branch.
2023-08-25 13:44:59 +03:00
break;
case FIL_PAGE_TYPE_ZBLOB:
case FIL_PAGE_TYPE_ZBLOB2:
case FIL_PAGE_INDEX:
case FIL_PAGE_RTREE:
break;
default:
ib::error() << "The compressed page to be"
" evicted seems corrupt:";
ut_print_buf(stderr, page, srv_page_size);
ib::error() << "Possibly older version of"
" the page:";
ut_print_buf(stderr, bpage->zip.data,
bpage->zip_size());
putc('\n', stderr);
ut_error;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
} else {
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_a(!bpage->oldest_modification());
Merge 10.3 into 10.4
2020-07-02 07:39:33 +03:00
MEM_CHECK_ADDRESSABLE(bpage->zip.data, bpage->zip_size());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
ut_ad(!bpage->in_zip_hash);
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
buf_pool.page_hash.remove(chain, bpage);
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
page_hash_latch& hash_lock = buf_pool.page_hash.lock_get(chain);
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
if (UNIV_UNLIKELY(!bpage->frame)) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_ad(!bpage->in_free_list);
ut_ad(!bpage->in_LRU_list);
ut_a(bpage->zip.data);
MDEV-18493 Remove page_size_t MySQL 5.7 introduced the class page_size_t and increased the size of buffer pool page descriptors by introducing this object to them. Maybe the intention of this exercise was to prepare for a future where the buffer pool could accommodate multiple page sizes. But that future never arrived, not even in MySQL 8.0. It is much easier to manage a pool of a single page size, and typically all storage devices of an InnoDB instance benefit from using the same page size. Let us remove page_size_t from MariaDB Server. This will make it easier to remove support for ROW_FORMAT=COMPRESSED (or make it a compile-time option) in the future, just by removing various occurrences of zip_size.
2019-02-06 19:50:11 +02:00
ut_a(bpage->zip.ssize);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_ad(!bpage->oldest_modification());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-26769 InnoDB does not support hardware lock elision This implements memory transaction support for: * Intel Restricted Transactional Memory (RTM), also known as TSX-NI (Transactional Synchronization Extensions New Instructions) * POWER v2.09 Hardware Trace Monitor (HTM) on GNU/Linux transactional_lock_guard, transactional_shared_lock_guard: RAII lock guards that try to elide the lock acquisition when transactional memory is available. buf_pool.page_hash: Try to elide latches whenever feasible. Related to the InnoDB change buffer and ROW_FORMAT=COMPRESSED tables, this is not always possible. In buf_page_get_low(), memory transactions only work reasonably well for validating a guessed block address. TMLockGuard, TMLockTrxGuard, TMLockMutexGuard: RAII lock guards that try to elide lock_sys.latch and related latches.
2021-10-22 12:38:45 +03:00
hash_lock.unlock();
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_pool_mutex_exit_forbid();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_buddy_free(bpage->zip.data, bpage->zip_size());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_pool_mutex_exit_allow();
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
bpage->lock.free();
ut_free(bpage);
return false;
} else {
MDEV-21133 Optimize access to InnoDB page header fields Introduce memcpy_aligned<N>(), memcmp_aligned<N>(), memset_aligned<N>() and use them for accessing InnoDB page header fields that are known to be aligned. MY_ASSUME_ALIGNED(): Wrapper for the GCC/clang __builtin_assume_aligned(). Nothing similar seems to exist in Microsoft Visual Studio, and the C++20 std::assume_aligned is not available to us yet. Explicitly specified alignment guarantees allow compilers to generate faster code on platforms with strict alignment rules, instead of emitting calls to potentially unaligned memcpy(), memcmp(), or memset().
2019-11-26 10:14:07 +02:00
static_assert(FIL_NULL == 0xffffffffU, "fill pattern");
static_assert(FIL_PAGE_OFFSET % 4 == 0, "alignment");
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
memset_aligned<4>(bpage->frame + FIL_PAGE_OFFSET, 0xff, 4);
MDEV-21133 Optimize access to InnoDB page header fields Introduce memcpy_aligned<N>(), memcmp_aligned<N>(), memset_aligned<N>() and use them for accessing InnoDB page header fields that are known to be aligned. MY_ASSUME_ALIGNED(): Wrapper for the GCC/clang __builtin_assume_aligned(). Nothing similar seems to exist in Microsoft Visual Studio, and the C++20 std::assume_aligned is not available to us yet. Explicitly specified alignment guarantees allow compilers to generate faster code on platforms with strict alignment rules, instead of emitting calls to potentially unaligned memcpy(), memcmp(), or memset().
2019-11-26 10:14:07 +02:00
static_assert(FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID % 4 == 2,
"not perfect alignment");
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
memset_aligned<2>(bpage->frame
MDEV-21133 Optimize access to InnoDB page header fields Introduce memcpy_aligned<N>(), memcmp_aligned<N>(), memset_aligned<N>() and use them for accessing InnoDB page header fields that are known to be aligned. MY_ASSUME_ALIGNED(): Wrapper for the GCC/clang __builtin_assume_aligned(). Nothing similar seems to exist in Microsoft Visual Studio, and the C++20 std::assume_aligned is not available to us yet. Explicitly specified alignment guarantees allow compilers to generate faster code on platforms with strict alignment rules, instead of emitting calls to potentially unaligned memcpy(), memcmp(), or memset().
2019-11-26 10:14:07 +02:00
+ FIL_PAGE_ARCH_LOG_NO_OR_SPACE_ID, 0xff, 4);
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
MEM_UNDEFINED(bpage->frame, srv_page_size);
bpage->set_state(buf_page_t::REMOVE_HASH);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-26200 buf_pool.flush_list corrupted by buffer pool resizing or ROW_FORMAT=COMPRESSED The lazy deletion of clean blocks from buf_pool.flush_list that was introduced in commit 6441bc614a99f5cd6357c8a23b9f583c56d0a90c (MDEV-25113) introduced a race condition around the function buf_flush_relocate_on_flush_list(). The test innodb_zip.wl5522_debug_zip as well as the buffer pool resizing tests would occasionally fail in debug builds due to buf_pool.flush_list.count disagreeing with the actual length of the doubly-linked list. The safe procedure for relocating a block in buf_pool.flush_list should be as follows, now that we implement lazy deletion from buf_pool.flush_list: 1. Acquire buf_pool.mutex. 2. Acquire the exclusive buf_pool.page_hash.latch. 3. Acquire buf_pool.flush_list_mutex. 4. Copy the block descriptor. 5. Invoke buf_flush_relocate_on_flush_list(). 6. Release buf_pool.flush_list_mutex. buf_flush_relocate_on_flush_list(): Assert that buf_pool.flush_list_mutex is being held. Invoke buf_page_t::oldest_modification() only once, using std::memory_order_relaxed, now that the mutex protects us. buf_LRU_free_page(), buf_LRU_block_remove_hashed(): Avoid an unlock-lock cycle on hash_lock. (We must not acquire hash_lock while already holding buf_pool.flush_list_mutex, because that could lead to a deadlock due to latching order violation.)
2021-07-22 08:34:49 +03:00
if (!zip) {
return true;
}
MDEV-26769 InnoDB does not support hardware lock elision This implements memory transaction support for: * Intel Restricted Transactional Memory (RTM), also known as TSX-NI (Transactional Synchronization Extensions New Instructions) * POWER v2.09 Hardware Trace Monitor (HTM) on GNU/Linux transactional_lock_guard, transactional_shared_lock_guard: RAII lock guards that try to elide the lock acquisition when transactional memory is available. buf_pool.page_hash: Try to elide latches whenever feasible. Related to the InnoDB change buffer and ROW_FORMAT=COMPRESSED tables, this is not always possible. In buf_page_get_low(), memory transactions only work reasonably well for validating a guessed block address. TMLockGuard, TMLockTrxGuard, TMLockMutexGuard: RAII lock guards that try to elide lock_sys.latch and related latches.
2021-10-22 12:38:45 +03:00
hash_lock.unlock();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-26200 buf_pool.flush_list corrupted by buffer pool resizing or ROW_FORMAT=COMPRESSED The lazy deletion of clean blocks from buf_pool.flush_list that was introduced in commit 6441bc614a99f5cd6357c8a23b9f583c56d0a90c (MDEV-25113) introduced a race condition around the function buf_flush_relocate_on_flush_list(). The test innodb_zip.wl5522_debug_zip as well as the buffer pool resizing tests would occasionally fail in debug builds due to buf_pool.flush_list.count disagreeing with the actual length of the doubly-linked list. The safe procedure for relocating a block in buf_pool.flush_list should be as follows, now that we implement lazy deletion from buf_pool.flush_list: 1. Acquire buf_pool.mutex. 2. Acquire the exclusive buf_pool.page_hash.latch. 3. Acquire buf_pool.flush_list_mutex. 4. Copy the block descriptor. 5. Invoke buf_flush_relocate_on_flush_list(). 6. Release buf_pool.flush_list_mutex. buf_flush_relocate_on_flush_list(): Assert that buf_pool.flush_list_mutex is being held. Invoke buf_page_t::oldest_modification() only once, using std::memory_order_relaxed, now that the mutex protects us. buf_LRU_free_page(), buf_LRU_block_remove_hashed(): Avoid an unlock-lock cycle on hash_lock. (We must not acquire hash_lock while already holding buf_pool.flush_list_mutex, because that could lead to a deadlock due to latching order violation.)
2021-07-22 08:34:49 +03:00
if (bpage->zip.data) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/* Free the compressed page. */
void* data = bpage->zip.data;
bpage->zip.data = NULL;
ut_ad(!bpage->in_free_list);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_ad(!bpage->oldest_modification());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_ad(!bpage->in_LRU_list);
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_pool_mutex_exit_forbid();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_buddy_free(data, bpage->zip_size());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_pool_mutex_exit_allow();
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
page_zip_set_size(&bpage->zip, 0);
}
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
return true;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
}
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
/** Release and evict a corrupted page.
MDEV-13542: Crashing on corrupted page is unhelpful The approach to handling corruption that was chosen by Oracle in commit 177d8b0c125b841c0650d27d735e3b87509dc286 is not really useful. Not only did it actually fail to prevent InnoDB from crashing, but it is making things worse by blocking attempts to rescue data from or rebuild a partially readable table. We will try to prevent crashes in a different way: by propagating errors up the call stack. We will never mark the clustered index persistently corrupted, so that data recovery may be attempted by reading from the table, or by rebuilding the table. This should also fix MDEV-13680 (crash on btr_page_alloc() failure); it was extensively tested with innodb_file_per_table=0 and a non-autoextend system tablespace. We should now avoid crashes in many cases, such as when a page cannot be read or allocated, or an inconsistency is detected when attempting to update multiple pages. We will not crash on double-free, such as on the recovery of DDL in system tablespace in case something was corrupted. Crashes on corrupted data are still possible. The fault injection mechanism that is introduced in the subsequent commit may help catch more of them. buf_page_import_corrupt_failure: Remove the fault injection, and instead corrupt some pages using Perl code in the tests. btr_cur_pessimistic_insert(): Always reserve extents (except for the change buffer), in order to prevent a subsequent allocation failure. btr_pcur_open_at_rnd_pos(): Merged to the only caller ibuf_merge_pages(). btr_assert_not_corrupted(), btr_corruption_report(): Remove. Similar checks are already part of btr_block_get(). FSEG_MAGIC_N_BYTES: Replaces FSEG_MAGIC_N_VALUE. dict_hdr_get(), trx_rsegf_get_new(), trx_undo_page_get(), trx_undo_page_get_s_latched(): Replaced with error-checking calls. trx_rseg_t::get(mtr_t*): Replaces trx_rsegf_get(). trx_rseg_header_create(): Let the caller update the TRX_SYS page if needed. trx_sys_create_sys_pages(): Merged with trx_sysf_create(). dict_check_tablespaces_and_store_max_id(): Do not access DICT_HDR_MAX_SPACE_ID, because it was already recovered in dict_boot(). Merge dict_check_sys_tables() with this function. dir_pathname(): Replaces os_file_make_new_pathname(). row_undo_ins_remove_sec(): Do not modify the undo page by adding a terminating NUL byte to the record. btr_decryption_failed(): Report decryption failures dict_set_corrupted_by_space(), dict_set_encrypted_by_space(), dict_set_corrupted_index_cache_only(): Remove. dict_set_corrupted(): Remove the constant parameter dict_locked=false. Never flag the clustered index corrupted in SYS_INDEXES, because that would deny further access to the table. It might be possible to repair the table by executing ALTER TABLE or OPTIMIZE TABLE, in case no B-tree leaf page is corrupted. dict_table_skip_corrupt_index(), dict_table_next_uncorrupted_index(), row_purge_skip_uncommitted_virtual_index(): Remove, and refactor the callers to read dict_index_t::type only once. dict_table_is_corrupted(): Remove. dict_index_t::is_btree(): Determine if the index is a valid B-tree. BUF_GET_NO_LATCH, BUF_EVICT_IF_IN_POOL: Remove. UNIV_BTR_DEBUG: Remove. Any inconsistency will no longer trigger assertion failures, but error codes being returned. buf_corrupt_page_release(): Replaced with a direct call to buf_pool.corrupted_evict(). fil_invalid_page_access_msg(): Never crash on an invalid read; let the caller of buf_page_get_gen() decide. btr_pcur_t::restore_position(): Propagate failure status to the caller by returning CORRUPTED. opt_search_plan_for_table(): Simplify the code. row_purge_del_mark(), row_purge_upd_exist_or_extern_func(), row_undo_ins_remove_sec_rec(), row_undo_mod_upd_del_sec(), row_undo_mod_del_mark_sec(): Avoid mem_heap_create()/mem_heap_free() when no secondary indexes exist. row_undo_mod_upd_exist_sec(): Simplify the code. row_upd_clust_step(), dict_load_table_one(): Return DB_TABLE_CORRUPT if the clustered index (and therefore the table) is corrupted, similar to what we do in row_insert_for_mysql(). fut_get_ptr(): Replace with buf_page_get_gen() calls. buf_page_get_gen(): Return nullptr and *err=DB_CORRUPTION if the page is marked as freed. For other modes than BUF_GET_POSSIBLY_FREED or BUF_PEEK_IF_IN_POOL this will trigger a debug assertion failure. For BUF_GET_POSSIBLY_FREED, we will return nullptr for freed pages, so that the callers can be simplified. The purge of transaction history will be a new user of BUF_GET_POSSIBLY_FREED, to avoid crashes on corrupted data. buf_page_get_low(): Never crash on a corrupted page, but simply return nullptr. fseg_page_is_allocated(): Replaces fseg_page_is_free(). fts_drop_common_tables(): Return an error if the transaction was rolled back. fil_space_t::set_corrupted(): Report a tablespace as corrupted if it was not reported already. fil_space_t::io(): Invoke fil_space_t::set_corrupted() to report out-of-bounds page access or other errors. Clean up mtr_t::page_lock() buf_page_get_low(): Validate the page identifier (to check for recently read corrupted pages) after acquiring the page latch. buf_page_t::read_complete(): Flag uninitialized (all-zero) pages with DB_FAIL. Return DB_PAGE_CORRUPTED on page number mismatch. mtr_t::defer_drop_ahi(): Renamed from mtr_defer_drop_ahi(). recv_sys_t::free_corrupted_page(): Only set_corrupt_fs() if any log records exist for the page. We do not mind if read-ahead produces corrupted (or all-zero) pages that were not actually needed during recovery. recv_recover_page(): Return whether the operation succeeded. recv_sys_t::recover_low(): Simplify the logic. Check for recovery error. Thanks to Matthias Leich for testing this extensively and to the authors of https://rr-project.org for making it easy to diagnose and fix any failures that were found during the testing.
2022-06-06 14:03:22 +03:00
@param bpage x-latched page that was found corrupted
@param state expected current state of the page */
ATTRIBUTE_COLD
void buf_pool_t::corrupted_evict(buf_page_t *bpage, uint32_t state)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
const page_id_t id{bpage->id()};
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
buf_pool_t::hash_chain &chain= buf_pool.page_hash.cell_get(id.fold());
page_hash_latch &hash_lock= buf_pool.page_hash.lock_get(chain);
MDEV-29911 InnoDB recovery and mariadb-backup --prepare fail to report detailed progress The progress reporting of InnoDB crash recovery was rather intermittent. Nothing was reported during the single-threaded log record parsing, which could consume minutes when parsing a large log. During log application, there only was progress reporting in background threads that would be invoked on data page read completion. The progress reporting here will be detailed like this: InnoDB: Starting crash recovery from checkpoint LSN=503549688 InnoDB: Parsed redo log up to LSN=1990840177; to recover: 124806 pages InnoDB: Parsed redo log up to LSN=2729777071; to recover: 186123 pages InnoDB: Parsed redo log up to LSN=3488599173; to recover: 248397 pages InnoDB: Parsed redo log up to LSN=4177856618; to recover: 306469 pages InnoDB: Multi-batch recovery needed at LSN 4189599815 InnoDB: End of log at LSN=4483551634 InnoDB: To recover: LSN 4189599815/4483551634; 307490 pages InnoDB: To recover: LSN 4189599815/4483551634; 197159 pages InnoDB: To recover: LSN 4189599815/4483551634; 67623 pages InnoDB: Parsed redo log up to LSN=4353924218; to recover: 102083 pages ... InnoDB: log sequence number 4483551634 ... The previous messages "Starting a batch to recover" or "Starting a final batch to recover" will be replaced by "To recover: ... pages" messages. If a batch lasts longer than 15 seconds, then there will be progress reports every 15 seconds, showing the number of remaining pages. For the non-final batch, the "To recover:" message includes two end LSN: that of the batch, and of the recovered log. This is the primary measure of progress. The batch will end once the number of pages to recover reaches 0. If recovery is possible in a single batch, the output will look like this, with a shorter "To recover:" message that counts only the remaining pages: InnoDB: Starting crash recovery from checkpoint LSN=503549688 InnoDB: Parsed redo log up to LSN=1998701027; to recover: 125560 pages InnoDB: Parsed redo log up to LSN=2734136874; to recover: 186446 pages InnoDB: Parsed redo log up to LSN=3499505504; to recover: 249378 pages InnoDB: Parsed redo log up to LSN=4183247844; to recover: 306964 pages InnoDB: End of log at LSN=4483551634 ... InnoDB: To recover: 331797 pages ... InnoDB: log sequence number 4483551634 ... We will also speed up recovery by improving the memory management and implementing multi-threaded recovery of data pages that will not need to be read into the buffer pool ("fake read"). Log application in the "fake read" threads will be protected by an atomic being_recovered field and exclusive buf_page_t::latch. Recovery will reserve for data pages two thirds of the buffer pool, or 256 pages, whichever is smaller. Previously, we could only use at most one third of the buffer pool for buffered log records. This would typically mean that with large buffer pools, recovery unnecessary consisted of multiple batches. If recovery runs out of memory, it will "roll back" or "rewind" the current mini-transaction. The recv_sys.lsn and recv_sys.pages will correspond to the "out of memory LSN", at the end of the previous complete mini-transaction. If recovery runs out of memory while executing the final recovery batch, we can simply invoke recv_sys.apply(false) to make room, and resume parsing. If recovery runs out of memory before the final batch, we will scan the redo log to the end (recv_sys.scanned_lsn) and check for any missing or inconsistent files. If recv_init_crash_recovery_spaces() does not report any potentially missing tablespaces, we can make use of the already stored recv_sys.pages and only rewind to the "out of memory LSN". Else, we must keep parsing and invoking recv_validate_tablespace() until an error has been found or everything has been resolved, and ultimatily rewind to to the checkpoint LSN. recv_sys_t::pages_it: A cached iterator to recv_sys.pages recv_sys_t::parse_mtr(): Remove an ATTRIBUTE_NOINLINE that would prevent tail call optimization in recv_sys_t::parse_pmem(). recv_sys_t::parse(), recv_sys_t::parse_mtr(), recv_sys_t::parse_pmem(): Add template<bool store> parameter. Redo log record parsing (store=false) is better specialized from store=true (with bool if_exists) so that we can avoid some conditional branches in frequently invoked low-level code. recv_sys_t::is_memory_exhausted(): Remove. The special parse() status GOT_OOM will report out-of-memory situation at the low level. recv_sys_t::rewind(), page_recv_t::recs_t::rewind(): Remove all log starting with a specific LSN. recv_scan_log(): Separate some code for only parsing, not storing log. In rewound_lsn, remember the LSN at which last_phase=false recovery ran out of memory. This is where the next call to recv_scan_log() will resume storing the log. This replaces recv_sys.last_stored_lsn. recv_sys_t::parse(): Evaluate the template parameter store in a few more cases, to allow dead code to be eliminated at compile time. recv_sys_t::scanned_lsn: The end of the log found by recv_scan_log(). The special value 1 means that recv_sys has been initialized but no log has been parsed. IORequest::write_complete(), IORequest::read_complete(): Replaces fil_aio_callback(). read_io_callback(), write_io_callback(): Replaces io_callback(). IORequest::fake_read_complete(), fake_io_callback(), os_fake_read(): Process a "fake read" request for concurrent recovery. recv_sys_t::apply_batch(): Choose a number of successive pages for a recovery batch. recv_sys_t::erase(recv_sys_t::map::iterator): Remove log records for a page whose recovery is not in progress. Log application threads will not invoke this; they will only set being_recovered=-1 to indicate that the entry is no longer needed. recv_sys_t::garbage_collect(): Remove all being_recovered=-1 entries. recv_sys_t::wait_for_pool(): Wait for some space to become available in the buffer pool. mlog_init_t::mark_ibuf_exist(): Avoid calls to recv_sys::recover_low() via ibuf_page_exists() and buf_page_get_low(). Such calls would lead to double locking of recv_sys.mutex, which depending on implementation could cause a deadlock. We will use lower-level calls to look up index pages. buf_LRU_block_remove_hashed(): Disable consistency checks for freed ROW_FORMAT=COMPRESSED pages. Their contents could be uninitialized garbage. This fixes an occasional failure of the test innodb.innodb_bulk_create_index_debug. Tested by: Matthias Leich
2023-05-19 15:15:38 +03:00
recv_sys.free_corrupted_page(id);
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
mysql_mutex_lock(&mutex);
MDEV-26769 InnoDB does not support hardware lock elision This implements memory transaction support for: * Intel Restricted Transactional Memory (RTM), also known as TSX-NI (Transactional Synchronization Extensions New Instructions) * POWER v2.09 Hardware Trace Monitor (HTM) on GNU/Linux transactional_lock_guard, transactional_shared_lock_guard: RAII lock guards that try to elide the lock acquisition when transactional memory is available. buf_pool.page_hash: Try to elide latches whenever feasible. Related to the InnoDB change buffer and ROW_FORMAT=COMPRESSED tables, this is not always possible. In buf_page_get_low(), memory transactions only work reasonably well for validating a guessed block address. TMLockGuard, TMLockTrxGuard, TMLockMutexGuard: RAII lock guards that try to elide lock_sys.latch and related latches.
2021-10-22 12:38:45 +03:00
hash_lock.lock();
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
ut_ad(!bpage->oldest_modification());
bpage->set_corrupt_id();
MDEV-28845 InnoDB: Failing assertion: bpage->can_relocate() in buf0lru.cc Since commit 0b47c126e31cddda1e94588799599e138400bcf8 (MDEV-13542) we treat all-zero pages as corrupted ones. During a stress test, a read-ahead of an all-zero page was triggered and the page read was completed concurrently with buf_page_create_low(). This caused the assertion to fail, because buf_page_create_low() was waiting for the page latch. buf_page_get_low(): Only invoke buf_pool_t::corrupted_evict() if the block was not already marked as corrupted. buf_page_create_low(): On page identifier mismatch, retry the buf_pool.page_hash lookup. buf_pool_t::corrupted_evict(): Set the state of the block to FREED so that a concurrent buf_page_get_low() will refuse to load the page. Wait for the page latch to be vacant before proceeding to remove the block from buf_pool.page_hash and buf_pool.LRU. page_id_t::set_corrupted(), page_id_t::is_corrupted(): Accessors for indicating a corrupted page identifier. Tested by Matthias Leich
2022-06-15 17:00:05 +03:00
auto unfix= state - buf_page_t::FREED;
MDEV-13542: Crashing on corrupted page is unhelpful The approach to handling corruption that was chosen by Oracle in commit 177d8b0c125b841c0650d27d735e3b87509dc286 is not really useful. Not only did it actually fail to prevent InnoDB from crashing, but it is making things worse by blocking attempts to rescue data from or rebuild a partially readable table. We will try to prevent crashes in a different way: by propagating errors up the call stack. We will never mark the clustered index persistently corrupted, so that data recovery may be attempted by reading from the table, or by rebuilding the table. This should also fix MDEV-13680 (crash on btr_page_alloc() failure); it was extensively tested with innodb_file_per_table=0 and a non-autoextend system tablespace. We should now avoid crashes in many cases, such as when a page cannot be read or allocated, or an inconsistency is detected when attempting to update multiple pages. We will not crash on double-free, such as on the recovery of DDL in system tablespace in case something was corrupted. Crashes on corrupted data are still possible. The fault injection mechanism that is introduced in the subsequent commit may help catch more of them. buf_page_import_corrupt_failure: Remove the fault injection, and instead corrupt some pages using Perl code in the tests. btr_cur_pessimistic_insert(): Always reserve extents (except for the change buffer), in order to prevent a subsequent allocation failure. btr_pcur_open_at_rnd_pos(): Merged to the only caller ibuf_merge_pages(). btr_assert_not_corrupted(), btr_corruption_report(): Remove. Similar checks are already part of btr_block_get(). FSEG_MAGIC_N_BYTES: Replaces FSEG_MAGIC_N_VALUE. dict_hdr_get(), trx_rsegf_get_new(), trx_undo_page_get(), trx_undo_page_get_s_latched(): Replaced with error-checking calls. trx_rseg_t::get(mtr_t*): Replaces trx_rsegf_get(). trx_rseg_header_create(): Let the caller update the TRX_SYS page if needed. trx_sys_create_sys_pages(): Merged with trx_sysf_create(). dict_check_tablespaces_and_store_max_id(): Do not access DICT_HDR_MAX_SPACE_ID, because it was already recovered in dict_boot(). Merge dict_check_sys_tables() with this function. dir_pathname(): Replaces os_file_make_new_pathname(). row_undo_ins_remove_sec(): Do not modify the undo page by adding a terminating NUL byte to the record. btr_decryption_failed(): Report decryption failures dict_set_corrupted_by_space(), dict_set_encrypted_by_space(), dict_set_corrupted_index_cache_only(): Remove. dict_set_corrupted(): Remove the constant parameter dict_locked=false. Never flag the clustered index corrupted in SYS_INDEXES, because that would deny further access to the table. It might be possible to repair the table by executing ALTER TABLE or OPTIMIZE TABLE, in case no B-tree leaf page is corrupted. dict_table_skip_corrupt_index(), dict_table_next_uncorrupted_index(), row_purge_skip_uncommitted_virtual_index(): Remove, and refactor the callers to read dict_index_t::type only once. dict_table_is_corrupted(): Remove. dict_index_t::is_btree(): Determine if the index is a valid B-tree. BUF_GET_NO_LATCH, BUF_EVICT_IF_IN_POOL: Remove. UNIV_BTR_DEBUG: Remove. Any inconsistency will no longer trigger assertion failures, but error codes being returned. buf_corrupt_page_release(): Replaced with a direct call to buf_pool.corrupted_evict(). fil_invalid_page_access_msg(): Never crash on an invalid read; let the caller of buf_page_get_gen() decide. btr_pcur_t::restore_position(): Propagate failure status to the caller by returning CORRUPTED. opt_search_plan_for_table(): Simplify the code. row_purge_del_mark(), row_purge_upd_exist_or_extern_func(), row_undo_ins_remove_sec_rec(), row_undo_mod_upd_del_sec(), row_undo_mod_del_mark_sec(): Avoid mem_heap_create()/mem_heap_free() when no secondary indexes exist. row_undo_mod_upd_exist_sec(): Simplify the code. row_upd_clust_step(), dict_load_table_one(): Return DB_TABLE_CORRUPT if the clustered index (and therefore the table) is corrupted, similar to what we do in row_insert_for_mysql(). fut_get_ptr(): Replace with buf_page_get_gen() calls. buf_page_get_gen(): Return nullptr and *err=DB_CORRUPTION if the page is marked as freed. For other modes than BUF_GET_POSSIBLY_FREED or BUF_PEEK_IF_IN_POOL this will trigger a debug assertion failure. For BUF_GET_POSSIBLY_FREED, we will return nullptr for freed pages, so that the callers can be simplified. The purge of transaction history will be a new user of BUF_GET_POSSIBLY_FREED, to avoid crashes on corrupted data. buf_page_get_low(): Never crash on a corrupted page, but simply return nullptr. fseg_page_is_allocated(): Replaces fseg_page_is_free(). fts_drop_common_tables(): Return an error if the transaction was rolled back. fil_space_t::set_corrupted(): Report a tablespace as corrupted if it was not reported already. fil_space_t::io(): Invoke fil_space_t::set_corrupted() to report out-of-bounds page access or other errors. Clean up mtr_t::page_lock() buf_page_get_low(): Validate the page identifier (to check for recently read corrupted pages) after acquiring the page latch. buf_page_t::read_complete(): Flag uninitialized (all-zero) pages with DB_FAIL. Return DB_PAGE_CORRUPTED on page number mismatch. mtr_t::defer_drop_ahi(): Renamed from mtr_defer_drop_ahi(). recv_sys_t::free_corrupted_page(): Only set_corrupt_fs() if any log records exist for the page. We do not mind if read-ahead produces corrupted (or all-zero) pages that were not actually needed during recovery. recv_recover_page(): Return whether the operation succeeded. recv_sys_t::recover_low(): Simplify the logic. Check for recovery error. Thanks to Matthias Leich for testing this extensively and to the authors of https://rr-project.org for making it easy to diagnose and fix any failures that were found during the testing.
2022-06-06 14:03:22 +03:00
auto s= bpage->zip.fix.fetch_sub(unfix) - unfix;
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
bpage->lock.x_unlock(true);
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
MDEV-28845 InnoDB: Failing assertion: bpage->can_relocate() in buf0lru.cc Since commit 0b47c126e31cddda1e94588799599e138400bcf8 (MDEV-13542) we treat all-zero pages as corrupted ones. During a stress test, a read-ahead of an all-zero page was triggered and the page read was completed concurrently with buf_page_create_low(). This caused the assertion to fail, because buf_page_create_low() was waiting for the page latch. buf_page_get_low(): Only invoke buf_pool_t::corrupted_evict() if the block was not already marked as corrupted. buf_page_create_low(): On page identifier mismatch, retry the buf_pool.page_hash lookup. buf_pool_t::corrupted_evict(): Set the state of the block to FREED so that a concurrent buf_page_get_low() will refuse to load the page. Wait for the page latch to be vacant before proceeding to remove the block from buf_pool.page_hash and buf_pool.LRU. page_id_t::set_corrupted(), page_id_t::is_corrupted(): Accessors for indicating a corrupted page identifier. Tested by Matthias Leich
2022-06-15 17:00:05 +03:00
while (s != buf_page_t::FREED || bpage->lock.is_locked_or_waiting())
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
{
MDEV-28845 InnoDB: Failing assertion: bpage->can_relocate() in buf0lru.cc Since commit 0b47c126e31cddda1e94588799599e138400bcf8 (MDEV-13542) we treat all-zero pages as corrupted ones. During a stress test, a read-ahead of an all-zero page was triggered and the page read was completed concurrently with buf_page_create_low(). This caused the assertion to fail, because buf_page_create_low() was waiting for the page latch. buf_page_get_low(): Only invoke buf_pool_t::corrupted_evict() if the block was not already marked as corrupted. buf_page_create_low(): On page identifier mismatch, retry the buf_pool.page_hash lookup. buf_pool_t::corrupted_evict(): Set the state of the block to FREED so that a concurrent buf_page_get_low() will refuse to load the page. Wait for the page latch to be vacant before proceeding to remove the block from buf_pool.page_hash and buf_pool.LRU. page_id_t::set_corrupted(), page_id_t::is_corrupted(): Accessors for indicating a corrupted page identifier. Tested by Matthias Leich
2022-06-15 17:00:05 +03:00
ut_ad(s >= buf_page_t::FREED);
ut_ad(s < buf_page_t::UNFIXED);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
/* Wait for other threads to release the fix count
before releasing the bpage from LRU list. */
MDEV-22871: Reduce InnoDB buf_pool.page_hash contention The rw_lock_s_lock() calls for the buf_pool.page_hash became a clear bottleneck after MDEV-15053 reduced the contention on buf_pool.mutex. We will replace that use of rw_lock_t with a special implementation that is optimized for memory bus traffic. The hash_table_locks instrumentation will be removed. buf_pool_t::page_hash: Use a special implementation whose API is compatible with hash_table_t, and store the custom rw-locks directly in buf_pool.page_hash.array, intentionally sharing cache lines with the hash table pointers. rw_lock: A low-level rw-lock implementation based on std::atomic<uint32_t> where read_trylock() becomes a simple fetch_add(1). buf_pool_t::page_hash_latch: The special of rw_lock for the page_hash. buf_pool_t::page_hash_latch::read_lock(): Assert that buf_pool.mutex is not being held by the caller. buf_pool_t::page_hash_latch::write_lock() may be called while not holding buf_pool.mutex. buf_pool_t::watch_set() is such a caller. buf_pool_t::page_hash_latch::read_lock_wait(), page_hash_latch::write_lock_wait(): The spin loops. These will obey the global parameters innodb_sync_spin_loops and innodb_sync_spin_wait_delay. buf_pool_t::freed_page_hash: A singly linked list of copies of buf_pool.page_hash that ever existed. The fact that we never free any buf_pool.page_hash.array guarantees that all page_hash_latch that ever existed will remain valid until shutdown. buf_pool_t::resize_hash(): Replaces buf_pool_resize_hash(). Prepend a shallow copy of the old page_hash to freed_page_hash. buf_pool_t::page_hash_table::n_cells: Declare as Atomic_relaxed. buf_pool_t::page_hash_table::lock(): Explain what prevents a race condition with buf_pool_t::resize_hash().
2020-06-18 13:38:30 +03:00
(void) LF_BACKOFF();
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
s= bpage->state();
}
MDEV-19435 buf_fix_count > 0 for corrupted page when it exits the LRU list Problem: ========= One of the purge thread access the corrupted page and tries to remove from LRU list. In the mean time, other purge threads are waiting for same page in buf_wait_for_read(). Assertion(buf_fix_count == 0) fails for the purge thread which tries to remove the page from LRU list. Solution: ======== - Set the page id as FIL_NULL to indicate the page is corrupted before removing the block from LRU list. Acquire hash lock for the particular page id and wait for the other threads to release buf_fix_count for the block. - Added the error check for btr_cur_open() in row_search_on_row_ref().
2019-06-13 16:31:06 +05:30
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
/* remove from LRU and page_hash */
if (buf_LRU_block_remove_hashed(bpage, id, chain, true))
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
buf_LRU_block_free_hashed_page(reinterpret_cast<buf_block_t*>(bpage));
MDEV-26826 Duplicated computations of buf_pool.page_hash addresses Since commit bd5a6403cace36c6ed428cde62e35adcd3f7e7d0 (MDEV-26033) we can actually calculate the buf_pool.page_hash cell and latch addresses while not holding buf_pool.mutex. buf_page_alloc_descriptor(): Remove the MEM_UNDEFINED. We now expect buf_page_t::hash to be zero-initialized. buf_pool_t::hash_chain: Dedicated data type for buf_pool.page_hash.array. buf_LRU_free_one_page(): Merged to the only caller buf_pool_t::corrupted_evict().
2021-10-22 12:33:37 +03:00
mysql_mutex_unlock(&mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
/** Update buf_pool.LRU_old_ratio.
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
@param[in] old_pct Reserve this percentage of
the buffer pool for "old" blocks
@param[in] adjust true=adjust the LRU list;
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
false=just assign buf_pool.LRU_old_ratio
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
during the initialization of InnoDB
@return updated old_pct */
uint buf_LRU_old_ratio_update(uint old_pct, bool adjust)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
uint ratio = old_pct * BUF_LRU_OLD_RATIO_DIV / 100;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
if (ratio < BUF_LRU_OLD_RATIO_MIN) {
ratio = BUF_LRU_OLD_RATIO_MIN;
} else if (ratio > BUF_LRU_OLD_RATIO_MAX) {
ratio = BUF_LRU_OLD_RATIO_MAX;
}
if (adjust) {
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_lock(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
if (ratio != buf_pool.LRU_old_ratio) {
buf_pool.LRU_old_ratio = ratio;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
if (UT_LIST_GET_LEN(buf_pool.LRU)
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
>= BUF_LRU_OLD_MIN_LEN) {
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_LRU_old_adjust_len();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
}
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_unlock(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
} else {
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
buf_pool.LRU_old_ratio = ratio;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
/* the reverse of
ratio = old_pct * BUF_LRU_OLD_RATIO_DIV / 100 */
return((uint) (ratio * 100 / (double) BUF_LRU_OLD_RATIO_DIV + 0.5));
}
/********************************************************************//**
Update the historical stats that we are collecting for LRU eviction
policy at the end of each interval. */
void
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
buf_LRU_stat_update()
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
buf_LRU_stat_t* item;
buf_LRU_stat_t cur_stat;
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
if (!buf_pool.freed_page_clock) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
goto func_exit;
}
/* Update the index. */
item = &buf_LRU_stat_arr[buf_LRU_stat_arr_ind];
buf_LRU_stat_arr_ind++;
buf_LRU_stat_arr_ind %= BUF_LRU_STAT_N_INTERVAL;
/* Add the current value and subtract the obsolete entry.
Since buf_LRU_stat_cur is not protected by any mutex,
it can be changing between adding to buf_LRU_stat_sum
and copying to item. Assign it to local variables to make
sure the same value assign to the buf_LRU_stat_sum
and item */
cur_stat = buf_LRU_stat_cur;
buf_LRU_stat_sum.io += cur_stat.io - item->io;
buf_LRU_stat_sum.unzip += cur_stat.unzip - item->unzip;
/* Put current entry in the array. */
memcpy(item, &cur_stat, sizeof *item);
func_exit:
/* Clear the current entry. */
memset(&buf_LRU_stat_cur, 0, sizeof buf_LRU_stat_cur);
}
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
#if defined __aarch64__&&defined __GNUC__&&__GNUC__==4&&!defined __clang__
/* Avoid GCC 4.8.5 internal compiler error "could not split insn".
We would only need this for buf_LRU_scan_and_free_block(),
but GCC 4.8.5 does not support pop_options. */
MDEV-27058 fixup: Fix MemorySanitizer, and GCC 4.8.5 ICE on ARMv8 buf_LRU_scan_and_free_block(): It turns out that even with -fno-expensive-optimizations, GCC 4.8.5 may fail to split an instruction. For the non-embedded server, -O1 would fail and -Og would seem to work, while the embedded server build seems to require -O0. buf_block_init(): Correct the MemorySanitizer instrumentation. buf_page_get_low(): Do not read dirty data from read-fixed blocks. These data races were identified by MemorySanitizer. If a read-fixed block is being accessed, we must acquire and release a page latch, so that the read-fix (and the exclusive page latch) will be released and it will be safe to read the page frame contents if needed, even before acquiring the final page latch. We do that in buf_read_ahead_linear() and for the allow_ibuf_merge check. mtr_t::page_lock(): Assert that the block is not read-fixed.
2021-11-20 13:57:23 +02:00
# pragma GCC optimize ("O0")
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
#endif
/** Try to free a replaceable block.
@param limit maximum number of blocks to scan
@return true if found and freed */
bool buf_LRU_scan_and_free_block(ulint limit)
{
mysql_mutex_assert_owner(&buf_pool.mutex);
return buf_LRU_free_from_unzip_LRU_list(limit) ||
buf_LRU_free_from_common_LRU_list(limit);
}
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
#ifdef UNIV_DEBUG
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
/** Validate the LRU list. */
void buf_LRU_validate()
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
ulint old_len;
ulint new_len;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_lock(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
if (UT_LIST_GET_LEN(buf_pool.LRU) >= BUF_LRU_OLD_MIN_LEN) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
ut_a(buf_pool.LRU_old);
old_len = buf_pool.LRU_old_len;
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
new_len = ut_min(UT_LIST_GET_LEN(buf_pool.LRU)
* buf_pool.LRU_old_ratio
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
/ BUF_LRU_OLD_RATIO_DIV,
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
UT_LIST_GET_LEN(buf_pool.LRU)
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
- (BUF_LRU_OLD_TOLERANCE
+ BUF_LRU_NON_OLD_MIN_LEN));
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
ut_a(old_len >= new_len - BUF_LRU_OLD_TOLERANCE);
ut_a(old_len <= new_len + BUF_LRU_OLD_TOLERANCE);
}
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
CheckInLRUList::validate();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
old_len = 0;
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
for (buf_page_t* bpage = UT_LIST_GET_FIRST(buf_pool.LRU);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
bpage != NULL;
bpage = UT_LIST_GET_NEXT(LRU, bpage)) {
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
ut_ad(bpage->in_file());
ut_ad(!bpage->frame
|| reinterpret_cast<buf_block_t*>(bpage)
->in_unzip_LRU_list
== bpage->belongs_to_unzip_LRU());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if (bpage->is_old()) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
const buf_page_t* prev
= UT_LIST_GET_PREV(LRU, bpage);
const buf_page_t* next
= UT_LIST_GET_NEXT(LRU, bpage);
if (!old_len++) {
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
ut_a(buf_pool.LRU_old == bpage);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
} else {
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_a(!prev || prev->is_old());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_a(!next || next->is_old());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
}
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
ut_a(buf_pool.LRU_old_len == old_len);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
CheckInFreeList::validate();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
for (buf_page_t* bpage = UT_LIST_GET_FIRST(buf_pool.free);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
bpage != NULL;
bpage = UT_LIST_GET_NEXT(list, bpage)) {
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
ut_a(bpage->state() == buf_page_t::NOT_USED);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
CheckUnzipLRUAndLRUList::validate();
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-21962 Allocate buf_pool statically Thanks to MDEV-15058, there is only one InnoDB buffer pool. Allocating buf_pool statically removes one level of pointer indirection and makes code more readable, and removes the awkward initialization of some buf_pool members. While doing this, we will also declare some buf_pool_t data members private and replace some functions with member functions. This is mostly affecting buffer pool resizing. This is not aiming to be a complete rewrite of buf_pool_t to a proper class. Most of the buffer pool interface, such as buf_page_get_gen(), will remain in the C programming style for now. buf_pool_t::withdrawing: Replaces buf_pool_withdrawing. buf_pool_t::withdraw_clock_: Replaces buf_withdraw_clock. buf_pool_t::create(): Repalces buf_pool_init(). buf_pool_t::close(): Replaces buf_pool_free(). buf_bool_t::will_be_withdrawn(): Replaces buf_block_will_be_withdrawn(), buf_frame_will_be_withdrawn(). buf_pool_t::clear_hash_index(): Replaces buf_pool_clear_hash_index(). buf_pool_t::get_n_pages(): Replaces buf_pool_get_n_pages(). buf_pool_t::validate(): Replaces buf_validate(). buf_pool_t::print(): Replaces buf_print(). buf_pool_t::block_from_ahi(): Replaces buf_block_from_ahi(). buf_pool_t::is_block_field(): Replaces buf_pointer_is_block_field(). buf_pool_t::is_block_mutex(): Replaces buf_pool_is_block_mutex(). buf_pool_t::is_block_lock(): Replaces buf_pool_is_block_lock(). buf_pool_t::is_obsolete(): Replaces buf_pool_is_obsolete(). buf_pool_t::io_buf: Make default-constructible. buf_pool_t::io_buf::create(): Delayed 'constructor' buf_pool_t::io_buf::close(): Early 'destructor' HazardPointer: Make default-constructible. Define all member functions inline, also for derived classes.
2020-03-18 21:48:00 +02:00
for (buf_block_t* block = UT_LIST_GET_FIRST(buf_pool.unzip_LRU);
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
block != NULL;
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
block = UT_LIST_GET_NEXT(unzip_LRU, block)) {
ut_ad(block->in_unzip_LRU_list);
ut_ad(block->page.in_LRU_list);
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
ut_a(block->page.belongs_to_unzip_LRU());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_unlock(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
#endif /* UNIV_DEBUG */
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
#if defined UNIV_DEBUG_PRINT || defined UNIV_DEBUG
MDEV-15058: Deprecate and ignore innodb_buffer_pool_instances Our benchmarking efforts indicate that the reasons for splitting the buf_pool in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 have mostly gone away, possibly as a result of mysql/mysql-server@ce6109ebfdedfdf185e391a0c97dc6d33867ed78 or similar work. Only in one write-heavy benchmark where the working set size is ten times the buffer pool size, the buf_pool->mutex would be less contended with 4 buffer pool instances than with 1 instance, in buf_page_io_complete(). That contention could be alleviated further by making more use of std::atomic and by splitting buf_pool_t::mutex further (MDEV-15053). We will deprecate and ignore the following parameters: innodb_buffer_pool_instances innodb_page_cleaners There will be only one buffer pool and one page cleaner task. In a number of INFORMATION_SCHEMA views, columns that indicated the buffer pool instance will be removed: information_schema.innodb_buffer_page.pool_id information_schema.innodb_buffer_page_lru.pool_id information_schema.innodb_buffer_pool_stats.pool_id information_schema.innodb_cmpmem.buffer_pool_instance information_schema.innodb_cmpmem_reset.buffer_pool_instance
2020-02-12 14:45:21 +02:00
/** Dump the LRU list to stderr. */
void buf_LRU_print()
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
{
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_lock(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
for (buf_page_t* bpage = UT_LIST_GET_FIRST(buf_pool.LRU);
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
bpage != NULL;
bpage = UT_LIST_GET_NEXT(LRU, bpage)) {
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
const page_id_t id(bpage->id());
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
fprintf(stderr, "BLOCK space %u page %u ",
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
id.space(), id.page_no());
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if (bpage->is_old()) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
fputs("old ", stderr);
}
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
const unsigned s = bpage->state();
if (s > buf_page_t::UNFIXED) {
fprintf(stderr, "fix %u ", s - buf_page_t::UNFIXED);
} else {
ut_ad(s == buf_page_t::UNFIXED
|| s == buf_page_t::REMOVE_HASH);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
if (bpage->oldest_modification()) {
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
fputs("modif. ", stderr);
}
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
if (const byte* frame = bpage->zip.data) {
Return uint16_t instead of ulint
2017-09-13 09:27:15 +03:00
fprintf(stderr, "\ntype %u size " ULINTPF
Merge InnoDB 5.7 from mysql-5.7.14. Contains also: MDEV-10549 mysqld: sql/handler.cc:2692: int handler::ha_index_first(uchar*): Assertion `table_share->tmp_table != NO_TMP_TABLE || m_lock_type != 2' failed. (branch bb-10.2-jan) Unlike MySQL, InnoDB still uses THR_LOCK in MariaDB MDEV-10548 Some of the debug sync waits do not work with InnoDB 5.7 (branch bb-10.2-jan) enable tests that were fixed in MDEV-10549 MDEV-10548 Some of the debug sync waits do not work with InnoDB 5.7 (branch bb-10.2-jan) fix main.innodb_mysql_sync - re-enable online alter for partitioned innodb tables
2016-09-06 09:43:16 +03:00
" index id " IB_ID_FMT "\n",
MDEV-12488 Remove type mismatch in InnoDB printf-like calls Alias the InnoDB ulint and lint data types to size_t and ssize_t, which are the standard names for the machine-word-width data types. Correspondingly, define ULINTPF as "%zu" and introduce ULINTPFx as "%zx". In this way, better compiler warnings for type mismatch are possible. Furthermore, use PRIu64 for that 64-bit format, and define the feature macro __STDC_FORMAT_MACROS to enable it on Red Hat systems. Fix some errors in error messages, and replace some error messages with assertions. Most notably, an IMPORT TABLESPACE error message in InnoDB was displaying the number of columns instead of the mismatching flags.
2017-04-21 05:51:27 +03:00
fil_page_get_type(frame),
MDEV-18493 Remove page_size_t MySQL 5.7 introduced the class page_size_t and increased the size of buffer pool page descriptors by introducing this object to them. Maybe the intention of this exercise was to prepare for a future where the buffer pool could accommodate multiple page sizes. But that future never arrived, not even in MySQL 8.0. It is much easier to manage a pool of a single page size, and typically all storage devices of an InnoDB instance benefit from using the same page size. Let us remove page_size_t from MariaDB Server. This will make it easier to remove support for ROW_FORMAT=COMPRESSED (or make it a compile-time option) in the future, just by removing various occurrences of zip_size.
2019-02-06 19:50:11 +02:00
bpage->zip_size(),
Merge InnoDB 5.7 from mysql-5.7.9. Contains also MDEV-10547: Test multi_update_innodb fails with InnoDB 5.7 The failure happened because 5.7 has changed the signature of the bool handler::primary_key_is_clustered() const virtual function ("const" was added). InnoDB was using the old signature which caused the function not to be used. MDEV-10550: Parallel replication lock waits/deadlock handling does not work with InnoDB 5.7 Fixed mutexing problem on lock_trx_handle_wait. Note that rpl_parallel and rpl_optimistic_parallel tests still fail. MDEV-10156 : Group commit tests fail on 10.2 InnoDB (branch bb-10.2-jan) Reason: incorrect merge MDEV-10550: Parallel replication can't sync with master in InnoDB 5.7 (branch bb-10.2-jan) Reason: incorrect merge
2016-08-12 11:17:45 +03:00
btr_page_get_index_id(frame));
MDEV-27058: Reduce the size of buf_block_t and buf_page_t buf_page_t::frame: Moved from buf_block_t::frame. All 'thin' buf_page_t describing compressed-only ROW_FORMAT=COMPRESSED pages will have frame=nullptr, while all 'fat' buf_block_t will have a non-null frame pointing to aligned innodb_page_size bytes. This eliminates the need for separate states for BUF_BLOCK_FILE_PAGE and BUF_BLOCK_ZIP_PAGE. buf_page_t::lock: Moved from buf_block_t::lock. That is, all block descriptors will have a page latch. The IO_PIN state that was used for discarding or creating the uncompressed page frame of a ROW_FORMAT=COMPRESSED block is replaced by a combination of read-fix and page X-latch. page_zip_des_t::fix: Replaces state_, buf_fix_count_, io_fix_, status of buf_page_t with a single std::atomic<uint32_t>. All modifications will use store(), fetch_add(), fetch_sub(). This space was previously wasted to alignment on 64-bit systems. We will use the following encoding that combines a state (partly read-fix or write-fix) and a buffer-fix count: buf_page_t::NOT_USED=0 (previously BUF_BLOCK_NOT_USED) buf_page_t::MEMORY=1 (previously BUF_BLOCK_MEMORY) buf_page_t::REMOVE_HASH=2 (previously BUF_BLOCK_REMOVE_HASH) buf_page_t::FREED=3 + fix: pages marked as freed in the file buf_page_t::UNFIXED=1U<<29 + fix: normal pages buf_page_t::IBUF_EXIST=2U<<29 + fix: normal pages; may need ibuf merge buf_page_t::REINIT=3U<<29 + fix: reinitialized pages (skip doublewrite) buf_page_t::READ_FIX=4U<<29 + fix: read-fixed pages (also X-latched) buf_page_t::WRITE_FIX=5U<<29 + fix: write-fixed pages (also U-latched) buf_page_t::WRITE_FIX_IBUF=6U<<29 + fix: write-fixed; may have ibuf buf_page_t::WRITE_FIX_REINIT=7U<<29 + fix: write-fixed (no doublewrite) buf_page_t::write_complete(): Change WRITE_FIX or WRITE_FIX_REINIT to UNFIXED, and WRITE_FIX_IBUF to IBUF_EXIST, before releasing the U-latch. buf_page_t::read_complete(): Renamed from buf_page_read_complete(). Change READ_FIX to UNFIXED or IBUF_EXIST, before releasing the X-latch. buf_page_t::can_relocate(): If the page latch is being held or waited for, or the block is buffer-fixed or io-fixed, return false. (The condition on the page latch is new.) Outside buf_page_get_gen(), buf_page_get_low() and buf_page_free(), we will acquire the page latch before fix(), and unfix() before unlocking. buf_page_t::flush(): Replaces buf_flush_page(). Optimize the handling of FREED pages. buf_pool_t::release_freed_page(): Assume that buf_pool.mutex is held by the caller. buf_page_t::is_read_fixed(), buf_page_t::is_write_fixed(): New predicates. buf_page_get_low(): Ignore guesses that are read-fixed because they may not yet be registered in buf_pool.page_hash and buf_pool.LRU. buf_page_optimistic_get(): Acquire latch before buffer-fixing. buf_page_make_young(): Leave read-fixed blocks alone, because they might not be registered in buf_pool.LRU yet. recv_sys_t::recover_deferred(), recv_sys_t::recover_low(): Possibly fix MDEV-26326, by holding a page X-latch instead of only buffer-fixing the page.
2021-11-16 19:55:06 +02:00
} else {
fprintf(stderr, "\ntype %u index id " IB_ID_FMT "\n",
fil_page_get_type(bpage->frame),
btr_page_get_index_id(bpage->frame));
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
}
MDEV-23399: Performance regression with write workloads The buffer pool refactoring in MDEV-15053 and MDEV-22871 shifted the performance bottleneck to the page flushing. The configuration parameters will be changed as follows: innodb_lru_flush_size=32 (new: how many pages to flush on LRU eviction) innodb_lru_scan_depth=1536 (old: 1024) innodb_max_dirty_pages_pct=90 (old: 75) innodb_max_dirty_pages_pct_lwm=75 (old: 0) Note: The parameter innodb_lru_scan_depth will only affect LRU eviction of buffer pool pages when a new page is being allocated. The page cleaner thread will no longer evict any pages. It used to guarantee that some pages will remain free in the buffer pool. Now, we perform that eviction 'on demand' in buf_LRU_get_free_block(). The parameter innodb_lru_scan_depth(srv_LRU_scan_depth) is used as follows: * When the buffer pool is being shrunk in buf_pool_t::withdraw_blocks() * As a buf_pool.free limit in buf_LRU_list_batch() for terminating the flushing that is initiated e.g., by buf_LRU_get_free_block() The parameter also used to serve as an initial limit for unzip_LRU eviction (evicting uncompressed page frames while retaining ROW_FORMAT=COMPRESSED pages), but now we will use a hard-coded limit of 100 or unlimited for invoking buf_LRU_scan_and_free_block(). The status variables will be changed as follows: innodb_buffer_pool_pages_flushed: This includes also the count of innodb_buffer_pool_pages_LRU_flushed and should work reliably, updated one by one in buf_flush_page() to give more real-time statistics. The function buf_flush_stats(), which we are removing, was not called in every code path. For both counters, we will use regular variables that are incremented in a critical section of buf_pool.mutex. Note that show_innodb_vars() directly links to the variables, and reads of the counters will *not* be protected by buf_pool.mutex, so you cannot get a consistent snapshot of both variables. The following INFORMATION_SCHEMA.INNODB_METRICS counters will be removed, because the page cleaner no longer deals with writing or evicting least recently used pages, and because the single-page writes have been removed: * buffer_LRU_batch_flush_avg_time_slot * buffer_LRU_batch_flush_avg_time_thread * buffer_LRU_batch_flush_avg_time_est * buffer_LRU_batch_flush_avg_pass * buffer_LRU_single_flush_scanned * buffer_LRU_single_flush_num_scan * buffer_LRU_single_flush_scanned_per_call When moving to a single buffer pool instance in MDEV-15058, we missed some opportunity to simplify the buf_flush_page_cleaner thread. It was unnecessarily using a mutex and some complex data structures, even though we always have a single page cleaner thread. Furthermore, the buf_flush_page_cleaner thread had separate 'recovery' and 'shutdown' modes where it was waiting to be triggered by some other thread, adding unnecessary latency and potential for hangs in relatively rarely executed startup or shutdown code. The page cleaner was also running two kinds of batches in an interleaved fashion: "LRU flush" (writing out some least recently used pages and evicting them on write completion) and the normal batches that aim to increase the MIN(oldest_modification) in the buffer pool, to help the log checkpoint advance. The buf_pool.flush_list flushing was being blocked by buf_block_t::lock for no good reason. Furthermore, if the FIL_PAGE_LSN of a page is ahead of log_sys.get_flushed_lsn(), that is, what has been persistently written to the redo log, we would trigger a log flush and then resume the page flushing. This would unnecessarily limit the performance of the page cleaner thread and trigger the infamous messages "InnoDB: page_cleaner: 1000ms intended loop took 4450ms. The settings might not be optimal" that were suppressed in commit d1ab89037a518fcffbc50c24e4bd94e4ec33aed0 unless log_warnings>2. Our revised algorithm will make log_sys.get_flushed_lsn() advance at the start of buf_flush_lists(), and then execute a 'best effort' to write out all pages. The flush batches will skip pages that were modified since the log was written, or are are currently exclusively locked. The MDEV-13670 message "page_cleaner: 1000ms intended loop took" message will be removed, because by design, the buf_flush_page_cleaner() should not be blocked during a batch for extended periods of time. We will remove the single-page flushing altogether. Related to this, the debug parameter innodb_doublewrite_batch_size will be removed, because all of the doublewrite buffer will be used for flushing batches. If a page needs to be evicted from the buffer pool and all 100 least recently used pages in the buffer pool have unflushed changes, buf_LRU_get_free_block() will execute buf_flush_lists() to write out and evict innodb_lru_flush_size pages. At most one thread will execute buf_flush_lists() in buf_LRU_get_free_block(); other threads will wait for that LRU flushing batch to finish. To improve concurrency, we will replace the InnoDB ib_mutex_t and os_event_t native mutexes and condition variables in this area of code. Most notably, this means that the buffer pool mutex (buf_pool.mutex) is no longer instrumented via any InnoDB interfaces. It will continue to be instrumented via PERFORMANCE_SCHEMA. For now, both buf_pool.flush_list_mutex and buf_pool.mutex will be declared with MY_MUTEX_INIT_FAST (PTHREAD_MUTEX_ADAPTIVE_NP). The critical sections of buf_pool.flush_list_mutex should be shorter than those for buf_pool.mutex, because in the worst case, they cover a linear scan of buf_pool.flush_list, while the worst case of a critical section of buf_pool.mutex covers a linear scan of the potentially much longer buf_pool.LRU list. mysql_mutex_is_owner(), safe_mutex_is_owner(): New predicate, usable with SAFE_MUTEX. Some InnoDB debug assertions need this predicate instead of mysql_mutex_assert_owner() or mysql_mutex_assert_not_owner(). buf_pool_t::n_flush_LRU, buf_pool_t::n_flush_list: Replaces buf_pool_t::init_flush[] and buf_pool_t::n_flush[]. The number of active flush operations. buf_pool_t::mutex, buf_pool_t::flush_list_mutex: Use mysql_mutex_t instead of ib_mutex_t, to have native mutexes with PERFORMANCE_SCHEMA and SAFE_MUTEX instrumentation. buf_pool_t::done_flush_LRU: Condition variable for !n_flush_LRU. buf_pool_t::done_flush_list: Condition variable for !n_flush_list. buf_pool_t::do_flush_list: Condition variable to wake up the buf_flush_page_cleaner when a log checkpoint needs to be written or the server is being shut down. Replaces buf_flush_event. We will keep using timed waits (the page cleaner thread will wake _at least_ once per second), because the calculations for innodb_adaptive_flushing depend on fixed time intervals. buf_dblwr: Allocate statically, and move all code to member functions. Use a native mutex and condition variable. Remove code to deal with single-page flushing. buf_dblwr_check_block(): Make the check debug-only. We were spending a significant amount of execution time in page_simple_validate_new(). flush_counters_t::unzip_LRU_evicted: Remove. IORequest: Make more members const. FIXME: m_fil_node should be removed. buf_flush_sync_lsn: Protect by std::atomic, not page_cleaner.mutex (which we are removing). page_cleaner_slot_t, page_cleaner_t: Remove many redundant members. pc_request_flush_slot(): Replaces pc_request() and pc_flush_slot(). recv_writer_thread: Remove. Recovery works just fine without it, if we simply invoke buf_flush_sync() at the end of each batch in recv_sys_t::apply(). recv_recovery_from_checkpoint_finish(): Remove. We can simply call recv_sys.debug_free() directly. srv_started_redo: Replaces srv_start_state. SRV_SHUTDOWN_FLUSH_PHASE: Remove. logs_empty_and_mark_files_at_shutdown() can communicate with the normal page cleaner loop via the new function flush_buffer_pool(). buf_flush_remove(): Assert that the calling thread is holding buf_pool.flush_list_mutex. This removes unnecessary mutex operations from buf_flush_remove_pages() and buf_flush_dirty_pages(), which replace buf_LRU_flush_or_remove_pages(). buf_flush_lists(): Renamed from buf_flush_batch(), with simplified interface. Return the number of flushed pages. Clarified comments and renamed min_n to max_n. Identify LRU batch by lsn=0. Merge all the functions buf_flush_start(), buf_flush_batch(), buf_flush_end() directly to this function, which was their only caller, and remove 2 unnecessary buf_pool.mutex release/re-acquisition that we used to perform around the buf_flush_batch() call. At the start, if not all log has been durably written, wait for a background task to do it, or start a new task to do it. This allows the log write to run concurrently with our page flushing batch. Any pages that were skipped due to too recent FIL_PAGE_LSN or due to them being latched by a writer should be flushed during the next batch, unless there are further modifications to those pages. It is possible that a page that we must flush due to small oldest_modification also carries a recent FIL_PAGE_LSN or is being constantly modified. In the worst case, all writers would then end up waiting in log_free_check() to allow the flushing and the checkpoint to complete. buf_do_flush_list_batch(): Clarify comments, and rename min_n to max_n. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_flush_space(): Auxiliary function to look up a tablespace for page flushing. buf_flush_page(): Defer the computation of space->full_crc32(). Never call log_write_up_to(), but instead skip persistent pages whose latest modification (FIL_PAGE_LSN) is newer than the redo log. Also skip pages on which we cannot acquire a shared latch without waiting. buf_flush_try_neighbors(): Do not bother checking buf_fix_count because buf_flush_page() will no longer wait for the page latch. Take the tablespace as a parameter, and only execute this function when innodb_flush_neighbors>0. Avoid repeated calls of page_id_t::fold(). buf_flush_relocate_on_flush_list(): Declare as cold, and push down a condition from the callers. buf_flush_check_neighbor(): Take id.fold() as a parameter. buf_flush_sync(): Ensure that the buf_pool.flush_list is empty, because the flushing batch will skip pages whose modifications have not yet been written to the log or were latched for modification. buf_free_from_unzip_LRU_list_batch(): Remove redundant local variables. buf_flush_LRU_list_batch(): Let the caller buf_do_LRU_batch() initialize the counters, and report n->evicted. Cache the last looked up tablespace. If neighbor flushing is not applicable, invoke buf_flush_page() directly, avoiding a page lookup in between. buf_do_LRU_batch(): Return the number of pages flushed. buf_LRU_free_page(): Only release and re-acquire buf_pool.mutex if adaptive hash index entries are pointing to the block. buf_LRU_get_free_block(): Do not wake up the page cleaner, because it will no longer perform any useful work for us, and we do not want it to compete for I/O while buf_flush_lists(innodb_lru_flush_size, 0) writes out and evicts at most innodb_lru_flush_size pages. (The function buf_do_LRU_batch() may complete after writing fewer pages if more than innodb_lru_scan_depth pages end up in buf_pool.free list.) Eliminate some mutex release-acquire cycles, and wait for the LRU flush batch to complete before rescanning. buf_LRU_check_size_of_non_data_objects(): Simplify the code. buf_page_write_complete(): Remove the parameter evict, and always evict pages that were part of an LRU flush. buf_page_create(): Take a pre-allocated page as a parameter. buf_pool_t::free_block(): Free a pre-allocated block. recv_sys_t::recover_low(), recv_sys_t::apply(): Preallocate the block while not holding recv_sys.mutex. During page allocation, we may initiate a page flush, which in turn may initiate a log flush, which would require acquiring log_sys.mutex, which should always be acquired before recv_sys.mutex in order to avoid deadlocks. Therefore, we must not be holding recv_sys.mutex while allocating a buffer pool block. BtrBulk::logFreeCheck(): Skip a redundant condition. row_undo_step(): Do not invoke srv_inc_activity_count() for every row that is being rolled back. It should suffice to invoke the function in trx_flush_log_if_needed() during trx_t::commit_in_memory() when the rollback completes. sync_check_enable(): Remove. We will enable innodb_sync_debug from the very beginning. Reviewed by: Vladislav Vaintroub
2020-10-15 12:10:42 +03:00
mysql_mutex_unlock(&buf_pool.mutex);
initial commit into innodb-5.6 mergetree
2014-02-26 19:11:54 +01:00
}
MDEV-15053 Reduce buf_pool_t::mutex contention User-visible changes: The INFORMATION_SCHEMA views INNODB_BUFFER_PAGE and INNODB_BUFFER_PAGE_LRU will report a dummy value FLUSH_TYPE=0 and will no longer report the PAGE_STATE value READY_FOR_USE. We will remove some fields from buf_page_t and move much code to member functions of buf_pool_t and buf_page_t, so that the access rules of data members can be enforced consistently. Evicting or adding pages in buf_pool.LRU will remain covered by buf_pool.mutex. Evicting or adding pages in buf_pool.page_hash will remain covered by both buf_pool.mutex and the buf_pool.page_hash X-latch. After this fix, buf_pool.page_hash lookups can entirely avoid acquiring buf_pool.mutex, only relying on buf_pool.hash_lock_get() S-latch. Similarly, buf_flush_check_neighbors() can will rely solely on buf_pool.mutex, no buf_pool.page_hash latch at all. The buf_pool.mutex is rather contended in I/O heavy benchmarks, especially when the workload does not fit in the buffer pool. The first attempt to alleviate the contention was the buf_pool_t::mutex split in commit 4ed7082eefe56b3e97e0edefb3df76dd7ef5e858 which introduced buf_block_t::mutex, which we are now removing. Later, multiple instances of buf_pool_t were introduced in commit c18084f71b02ea707c6461353e6cfc15d7553bc6 and recently removed by us in commit 1a6f708ec594ac0ae2dd30db926ab07b100fa24b (MDEV-15058). UNIV_BUF_DEBUG: Remove. This option to enable some buffer pool related debugging in otherwise non-debug builds has not been used for years. Instead, we have been using UNIV_DEBUG, which is enabled in CMAKE_BUILD_TYPE=Debug. buf_block_t::mutex, buf_pool_t::zip_mutex: Remove. We can mainly rely on std::atomic and the buf_pool.page_hash latches, and in some cases depend on buf_pool.mutex or buf_pool.flush_list_mutex just like before. We must always release buf_block_t::lock before invoking unfix() or io_unfix(), to prevent a glitch where a block that was added to the buf_pool.free list would apper X-latched. See commit c5883debd6ef440a037011c11873b396923e93c5 how this glitch was finally caught in a debug environment. We move some buf_pool_t::page_hash specific code from the ha and hash modules to buf_pool, for improved readability. buf_pool_t::close(): Assert that all blocks are clean, except on aborted startup or crash-like shutdown. buf_pool_t::validate(): No longer attempt to validate n_flush[] against the number of BUF_IO_WRITE fixed blocks, because buf_page_t::flush_type no longer exists. buf_pool_t::watch_set(): Replaces buf_pool_watch_set(). Reduce mutex contention by separating the buf_pool.watch[] allocation and the insert into buf_pool.page_hash. buf_pool_t::page_hash_lock<bool exclusive>(): Acquire a buf_pool.page_hash latch. Replaces and extends buf_page_hash_lock_s_confirm() and buf_page_hash_lock_x_confirm(). buf_pool_t::READ_AHEAD_PAGES: Renamed from BUF_READ_AHEAD_PAGES. buf_pool_t::curr_size, old_size, read_ahead_area, n_pend_reads: Use Atomic_counter. buf_pool_t::running_out(): Replaces buf_LRU_buf_pool_running_out(). buf_pool_t::LRU_remove(): Remove a block from the LRU list and return its predecessor. Incorporates buf_LRU_adjust_hp(), which was removed. buf_page_get_gen(): Remove a redundant call of fsp_is_system_temporary(), for mode == BUF_GET_IF_IN_POOL_OR_WATCH, which is only used by BTR_DELETE_OP (purge), which is never invoked on temporary tables. buf_free_from_unzip_LRU_list_batch(): Avoid redundant assignments. buf_LRU_free_from_unzip_LRU_list(): Simplify the loop condition. buf_LRU_free_page(): Clarify the function comment. buf_flush_check_neighbor(), buf_flush_check_neighbors(): Rewrite the construction of the page hash range. We will hold the buf_pool.mutex for up to buf_pool.read_ahead_area (at most 64) consecutive lookups of buf_pool.page_hash. buf_flush_page_and_try_neighbors(): Remove. Merge to its only callers, and remove redundant operations in buf_flush_LRU_list_batch(). buf_read_ahead_random(), buf_read_ahead_linear(): Rewrite. Do not acquire buf_pool.mutex, and iterate directly with page_id_t. ut_2_power_up(): Remove. my_round_up_to_next_power() is inlined and avoids any loops. fil_page_get_prev(), fil_page_get_next(), fil_addr_is_null(): Remove. buf_flush_page(): Add a fil_space_t* parameter. Minimize the buf_pool.mutex hold time. buf_pool.n_flush[] is no longer updated atomically with the io_fix, and we will protect most buf_block_t fields with buf_block_t::lock. The function buf_flush_write_block_low() is removed and merged here. buf_page_init_for_read(): Use static linkage. Initialize the newly allocated block and acquire the exclusive buf_block_t::lock while not holding any mutex. IORequest::IORequest(): Remove the body. We only need to invoke set_punch_hole() in buf_flush_page() and nowhere else. buf_page_t::flush_type: Remove. Replaced by IORequest::flush_type. This field is only used during a fil_io() call. That function already takes IORequest as a parameter, so we had better introduce for the rarely changing field. buf_block_t::init(): Replaces buf_page_init(). buf_page_t::init(): Replaces buf_page_init_low(). buf_block_t::initialise(): Initialise many fields, but keep the buf_page_t::state(). Both buf_pool_t::validate() and buf_page_optimistic_get() requires that buf_page_t::in_file() be protected atomically with buf_page_t::in_page_hash and buf_page_t::in_LRU_list. buf_page_optimistic_get(): Now that buf_block_t::mutex no longer exists, we must check buf_page_t::io_fix() after acquiring the buf_pool.page_hash lock, to detect whether buf_page_init_for_read() has been initiated. We will also check the io_fix() before acquiring hash_lock in order to avoid unnecessary computation. The field buf_block_t::modify_clock (protected by buf_block_t::lock) allows buf_page_optimistic_get() to validate the block. buf_page_t::real_size: Remove. It was only used while flushing pages of page_compressed tables. buf_page_encrypt(): Add an output parameter that allows us ot eliminate buf_page_t::real_size. Replace a condition with debug assertion. buf_page_should_punch_hole(): Remove. buf_dblwr_t::add_to_batch(): Replaces buf_dblwr_add_to_batch(). Add the parameter size (to replace buf_page_t::real_size). buf_dblwr_t::write_single_page(): Replaces buf_dblwr_write_single_page(). Add the parameter size (to replace buf_page_t::real_size). fil_system_t::detach(): Replaces fil_space_detach(). Ensure that fil_validate() will not be violated even if fil_system.mutex is released and reacquired. fil_node_t::complete_io(): Renamed from fil_node_complete_io(). fil_node_t::close_to_free(): Replaces fil_node_close_to_free(). Avoid invoking fil_node_t::close() because fil_system.n_open has already been decremented in fil_space_t::detach(). BUF_BLOCK_READY_FOR_USE: Remove. Directly use BUF_BLOCK_MEMORY. BUF_BLOCK_ZIP_DIRTY: Remove. Directly use BUF_BLOCK_ZIP_PAGE, and distinguish dirty pages by buf_page_t::oldest_modification(). BUF_BLOCK_POOL_WATCH: Remove. Use BUF_BLOCK_NOT_USED instead. This state was only being used for buf_page_t that are in buf_pool.watch. buf_pool_t::watch[]: Remove pointer indirection. buf_page_t::in_flush_list: Remove. It was set if and only if buf_page_t::oldest_modification() is nonzero. buf_page_decrypt_after_read(), buf_corrupt_page_release(), buf_page_check_corrupt(): Change the const fil_space_t* parameter to const fil_node_t& so that we can report the correct file name. buf_page_monitor(): Declare as an ATTRIBUTE_COLD global function. buf_page_io_complete(): Split to buf_page_read_complete() and buf_page_write_complete(). buf_dblwr_t::in_use: Remove. buf_dblwr_t::buf_block_array: Add IORequest::flush_t. buf_dblwr_sync_datafiles(): Remove. It was a useless wrapper of os_aio_wait_until_no_pending_writes(). buf_flush_write_complete(): Declare static, not global. Add the parameter IORequest::flush_t. buf_flush_freed_page(): Simplify the code. recv_sys_t::flush_lru: Renamed from flush_type and changed to bool. fil_read(), fil_write(): Replaced with direct use of fil_io(). fil_buffering_disabled(): Remove. Check srv_file_flush_method directly. fil_mutex_enter_and_prepare_for_io(): Return the resolved fil_space_t* to avoid a duplicated lookup in the caller. fil_report_invalid_page_access(): Clean up the parameters. fil_io(): Return fil_io_t, which comprises fil_node_t and error code. Always invoke fil_space_t::acquire_for_io() and let either the sync=true caller or fil_aio_callback() invoke fil_space_t::release_for_io(). fil_aio_callback(): Rewrite to replace buf_page_io_complete(). fil_check_pending_operations(): Remove a parameter, and remove some redundant lookups. fil_node_close_to_free(): Wait for n_pending==0. Because we no longer do an extra lookup of the tablespace between fil_io() and the completion of the operation, we must give fil_node_t::complete_io() a chance to decrement the counter. fil_close_tablespace(): Remove unused parameter trx, and document that this is only invoked during the error handling of IMPORT TABLESPACE. row_import_discard_changes(): Merged with the only caller, row_import_cleanup(). Do not lock up the data dictionary while invoking fil_close_tablespace(). logs_empty_and_mark_files_at_shutdown(): Do not invoke fil_close_all_files(), to avoid a !needs_flush assertion failure on fil_node_t::close(). innodb_shutdown(): Invoke os_aio_free() before fil_close_all_files(). fil_close_all_files(): Invoke fil_flush_file_spaces() to ensure proper durability. thread_pool::unbind(): Fix a crash that would occur on Windows after srv_thread_pool->disable_aio() and os_file_close(). This fix was submitted by Vladislav Vaintroub. Thanks to Matthias Leich and Axel Schwenke for extensive testing, Vladislav Vaintroub for helpful comments, and Eugene Kosov for a review.
2020-06-05 12:35:46 +03:00
#endif /* UNIV_DEBUG_PRINT || UNIV_DEBUG */
Reference in a new issue Copy permalink