mariadb/extra
Marko Mäkelä 44a1cb4046 MDEV-29445: Reimplement SET GLOBAL innodb_buffer_pool_size
We deprecate and ignore the parameter innodb_buffer_pool_chunk_size
and let the buffer pool size to be changed in arbitrary 1-megabyte
increments, all the way up to innodb_buffer_pool_size_max,
which must be specified at startup.

If innodb_buffer_pool_size_max is not specified, it will default to
twice the specified innodb_buffer_pool_size.

The buffer pool will be mapped in a contiguous memory area that
will be aligned and partitioned into extents of 8 MiB on 64-bit systems
and 2 MiB on 32-bit systems.

Within an extent, the first few innodb_page_size blocks contain
buf_block_t objects that will cover the page frames in the rest
of the extent. In this way, there is a trivial mapping between
page frames and block descriptors and we do not need any
lookup tables like buf_pool.zip_hash or buf_pool_t::chunk_t::map.

We will always allocate the same number of block descriptors for
an extent, even if we do not need all the buf_block_t in the last
extent in case the innodb_buffer_pool_size is not an integer multiple
of the of extents size.

The minimum innodb_buffer_pool_size is 256*5/4 pages. At the default
innodb_page_size=16k this corresponds to 5 MiB. However, now that the
innodb_buffer_pool_size includes the memory allocated for the block
descriptors, the minimum would be innodb_buffer_pool_size=6m.

When the buffer pool is shrunk, InnoDB will try to inform the operating
system that the underlying memory for part of the virtual address range
is no longer needed and may be zeroed out. On many POSIX-like systems this
is done by madvise(MADV_FREE) where available (Linux, FreeBSD, NetBSD,
OpenBSD, Apple macOS). On Microsoft Windows, VirtualFree(MEM_DECOMMIT)
is invoked.

Innodb_buffer_pool_resize_status: Remove. We will execute
buf_pool_t::resize() synchronously in the thread that is executing
SET GLOBAL innodb_buffer_pool_size. That operation will run until
it completes, or until a KILL statement is executed, the client
is disconnected, the buf_flush_page_cleaner() thread notices that
we are running out of memory, or the server is shut down.

opt_super_large_pages: Declare only on Solaris. Actually, this is
specific to the SPARC implementation of Solaris, but due to us not
having a Solaris development environment, we will not revise this
for other MMU and ISA.

my_large_virtual_alloc(): A new function, similar to my_large_malloc().
On Microsoft Windows, buffer pool resizing is disabled if large pages
are being used.

buf_pool_t::chunk_t::create(): Remove.

buf_pool_t::create(): Initialize all n_blocks of the buf_pool.free list.

buf_pool_t::allocate(): Renamed from buf_LRU_get_free_only().

buf_pool_t::LRU_warned: Changed to Atomic_relaxed<bool>,
only to be modified by the buf_flush_page_cleaner() thread.

buf_pool_t::LRU_shrink(): Check if buffer pool shrinking needs
to process a buffer page.

buf_pool_t::resize(): Always zero out b->page.zip.data.
Failure to do so would cause crashes or corruption in
the test innodb.innodb_buffer_pool_resize due to
duplicated allocation in the buddy system.
Before tarting to shrink the buffer pool, run one batch of
buf_flush_page_cleaner() in order to prevent LRU_warn().
Abort shrinking if the buf_flush_page_cleaner() has LRU_warned.

buf_pool_t::first_to_withdraw: The first block descriptor that is
out of the bounds of the shrunk buffer pool.

buf_pool_t::withdrawn: The list of withdrawn blocks.
If buf_pool_t::resize() is aborted, we must be able to resurrect
the withdrawn blocks in the free list.

buf_pool_t::contains_zip(): Added a parameter for the
number of least significant pointer bits to disregard,
so that we can find any pointers to within a block
that is supposed to be free.

buf_pool_t::is_shrinking(): Return the total number or blocks that
were withdrawn or are to be withdrawn.

buf_pool_t::to_withdraw(): Return the number of blocks that will need to
be withdrawn.

buf_pool_t::usable_size(): Number of usable pages, considering possible
in-progress attempt at shrinking the buffer pool.

buf_page_get_low(): Suppress a MemorySanitizer warning about
an uninitialized (typically all-zero) block->page.id().

buf_pool_t::get_info(): Replaces buf_stats_get_pool_info().

innodb_init_param(): Refactored. We must first compute
srv_page_size_shift and then determine the valid bounds of
innodb_buffer_pool_size.

buf_buddy_shrink(): Replaces buf_buddy_realloc().
Part of the work is deferred to buf_buddy_condense_free(),
which is being executed when we are not holding any
buf_pool.page_hash latch.

buf_buddy_condense_free(): Do not relocate blocks.

buf_buddy_free_low(): Do not care about buffer pool shrinking.
This will be handled by buf_buddy_shrink() and
buf_buddy_condense_free().

buf_buddy_alloc_zip(): Assert !buf_pool.contains_zip()
when we are allocating from the binary buddy system.
Previously we were asserting this on multiple recursion levels.

buf_buddy_block_free(), buf_buddy_free_low():
Assert !buf_pool.contains_zip().

buf_buddy_alloc_from(): Remove the redundant parameter j.

buf_flush_LRU_list_batch(): Add the parameter shrinking.
If we are shrinking, invoke buf_pool_t::LRU_shrink() to see
if we must keep going.

buf_do_LRU_batch(): Skip buf_free_from_unzip_LRU_list_batch()
if we are shrinking the buffer pool. In that case, we want
to minimize the page relocations and just finish as quickly
as possible.

trx_purge_attach_undo_recs(): Limit purge_sys.n_pages_handled()
in every iteration, in case the buffer pool is being shrunk
in the middle of a purge batch.
2025-02-19 11:07:48 +02:00
..
aws_sdk MDEV-23539: aws key plugin - fails to build 2020-10-26 14:59:42 +11:00
mariabackup MDEV-29445: Reimplement SET GLOBAL innodb_buffer_pool_size 2025-02-19 11:07:48 +02:00
readline Merge branch '5.5' into 10.1 2019-05-11 22:19:05 +03:00
wolfssl WolfSSL - make it compilable also with older versions of Windows SDK. 2025-01-24 12:39:00 +01:00
charset2html.c Merge branch '5.5' into 10.1 2019-05-11 22:19:05 +03:00
CMakeLists.txt Merge branch '10.5' into 10.6 2024-05-08 20:06:00 +02:00
comp_err.c MDEV-30810 errmsg-utf8.txt no longer uses charsets 2023-03-10 08:53:58 +11:00
innochecksum.cc Merge 10.6 into 10.11 2024-11-29 13:43:17 +02:00
my_print_defaults.c Merge 10.6 into 10.11 2024-11-29 13:43:17 +02:00
mysql_waitpid.c Added 'const' to arguments in get_one_option and find_typeset() 2021-02-08 12:16:29 +02:00
mysqld_safe_helper.c mysqld_safe_help - remove warning 2017-04-30 15:06:01 +04:00
perror.c MDEV-34714 perror-win test failure on localized Windows 2024-08-09 01:15:45 +02:00
replace.c Merge 10.4 into 10.5 2022-07-01 14:42:02 +03:00
resolve_stack_dump.c MDEV-22189: Change error messages inside code to have mariadb instead of 2021-05-24 11:38:13 +05:30
resolveip.c Added 'const' to arguments in get_one_option and find_typeset() 2021-02-08 12:16:29 +02:00