mariadb/storage/innobase/include/mtr0mtr.inl

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/*****************************************************************************
Copyright (c) 1995, 2014, Oracle and/or its affiliates. All Rights Reserved.
Copyright (c) 2017, 2021, MariaDB Corporation.
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.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1335 USA
*****************************************************************************/
/**************************************************//**
@file include/mtr0mtr.ic
Mini-transaction buffer
Created 11/26/1995 Heikki Tuuri
*******************************************************/
#include "buf0buf.h"
/** Check if a mini-transaction is dirtying a clean page.
@return true if the mtr is dirtying a clean 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
inline bool mtr_t::is_block_dirtied(const buf_block_t *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
ut_ad(block->page.state() == BUF_BLOCK_FILE_PAGE);
ut_ad(block->page.buf_fix_count());
return block->page.oldest_modification() <= 1;
}
/**
Pushes an object to an mtr memo stack. */
void
mtr_t::memo_push(void* object, mtr_memo_type_t type)
{
ut_ad(is_active());
ut_ad(object != NULL);
ut_ad(type >= MTR_MEMO_PAGE_S_FIX);
MDEV-23190 InnoDB data file extension is not crash-safe When InnoDB is extending a data file, it is updating the FSP_SIZE field in the first page of the data file. In commit 8451e09073e8b1a300f177d74a9e3a530776640a (MDEV-11556) we removed a work-around for this bug and made recovery stricter, by making it track changes to FSP_SIZE via redo log records, and extend the data files before any changes are being applied to them. It turns out that the function fsp_fill_free_list() is not crash-safe with respect to this when it is initializing the change buffer bitmap page (page 1, or generally, N*innodb_page_size+1). It uses a separate mini-transaction that is committed (and will be written to the redo log file) before the mini-transaction that actually extended the data file. Hence, recovery can observe a reference to a page that is beyond the current end of the data file. fsp_fill_free_list(): Initialize the change buffer bitmap page in the same mini-transaction. The rest of the changes are fixing a bug that the use of the separate mini-transaction was attempting to work around. Namely, we must ensure that no other thread will access the change buffer bitmap page before our mini-transaction has been committed and all page latches have been released. That is, for read-ahead as well as neighbour flushing, we must avoid accessing pages that might not yet be durably part of the tablespace. fil_space_t::committed_size: The size of the tablespace as persisted by mtr_commit(). fil_space_t::max_page_number_for_io(): Limit the highest page number for I/O batches to committed_size. MTR_MEMO_SPACE_X_LOCK: Replaces MTR_MEMO_X_LOCK for fil_space_t::latch. mtr_x_space_lock(): Replaces mtr_x_lock() for fil_space_t::latch. mtr_memo_slot_release_func(): When releasing MTR_MEMO_SPACE_X_LOCK, copy space->size to space->committed_size. In this way, read-ahead or flushing will never be invoked on pages that do not yet exist according to FSP_SIZE.
2020-07-17 15:55:45 +03:00
ut_ad(type <= MTR_MEMO_SPACE_X_LOCK);
ut_ad(ut_is_2pow(type));
/* If this mtr has x-fixed a clean page then we set
the made_dirty flag. This tells us if we need to
grab log_sys.flush_order_mutex at mtr_t::commit() so that we
can insert the dirtied page into the flush list. */
if ((type == MTR_MEMO_PAGE_X_FIX || type == MTR_MEMO_PAGE_SX_FIX)
&& !m_made_dirty) {
m_made_dirty = is_block_dirtied(
reinterpret_cast<const buf_block_t*>(object));
}
mtr_memo_slot_t* slot = m_memo.push<mtr_memo_slot_t*>(sizeof(*slot));
slot->type = type;
slot->object = object;
}
/**
Releases the (index tree) s-latch stored in an mtr memo after a
savepoint. */
void
mtr_t::release_s_latch_at_savepoint(
ulint savepoint,
rw_lock_t* lock)
{
ut_ad(is_active());
ut_ad(m_memo.size() > savepoint);
mtr_memo_slot_t* slot = m_memo.at<mtr_memo_slot_t*>(savepoint);
ut_ad(slot->object == lock);
ut_ad(slot->type == MTR_MEMO_S_LOCK);
rw_lock_s_unlock(lock);
slot->object = NULL;
}
/**
SX-latches the not yet latched block after a savepoint. */
void
mtr_t::sx_latch_at_savepoint(
ulint savepoint,
buf_block_t* block)
{
ut_ad(is_active());
ut_ad(m_memo.size() > savepoint);
ut_ad(!memo_contains_flagged(
block,
MTR_MEMO_PAGE_S_FIX
| MTR_MEMO_PAGE_X_FIX
| MTR_MEMO_PAGE_SX_FIX));
mtr_memo_slot_t* slot = m_memo.at<mtr_memo_slot_t*>(savepoint);
ut_ad(slot->object == block);
/* == RW_NO_LATCH */
ut_a(slot->type == MTR_MEMO_BUF_FIX);
rw_lock_sx_lock(&block->lock);
if (!m_made_dirty) {
m_made_dirty = is_block_dirtied(block);
}
slot->type = MTR_MEMO_PAGE_SX_FIX;
}
/**
X-latches the not yet latched block after a savepoint. */
void
mtr_t::x_latch_at_savepoint(
ulint savepoint,
buf_block_t* block)
{
ut_ad(is_active());
ut_ad(m_memo.size() > savepoint);
ut_ad(!memo_contains_flagged(
block,
MTR_MEMO_PAGE_S_FIX
| MTR_MEMO_PAGE_X_FIX
| MTR_MEMO_PAGE_SX_FIX));
mtr_memo_slot_t* slot = m_memo.at<mtr_memo_slot_t*>(savepoint);
ut_ad(slot->object == block);
/* == RW_NO_LATCH */
ut_a(slot->type == MTR_MEMO_BUF_FIX);
rw_lock_x_lock(&block->lock);
if (!m_made_dirty) {
m_made_dirty = is_block_dirtied(block);
}
slot->type = MTR_MEMO_PAGE_X_FIX;
}
/**
Releases the block in an mtr memo after a savepoint. */
void
mtr_t::release_block_at_savepoint(
ulint savepoint,
buf_block_t* block)
{
ut_ad(is_active());
mtr_memo_slot_t* slot = m_memo.at<mtr_memo_slot_t*>(savepoint);
ut_a(slot->object == block);
buf_page_release_latch(block, slot->type);
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
reinterpret_cast<buf_block_t*>(block)->unfix();
slot->object = NULL;
}