diff options
| author | Alexander Korotkov | 2025-04-02 09:44:24 +0000 |
|---|---|---|
| committer | Alexander Korotkov | 2025-04-02 09:44:24 +0000 |
| commit | bc22dc0e0ddc2dcb6043a732415019cc6b6bf683 (patch) | |
| tree | 34fbf986ac05c0655f894ec056c9aba4f49eed5e /src/include | |
| parent | b53b88109f94bd81ed0ac580035a936000bc2865 (diff) | |
Get rid of WALBufMappingLock
Allow multiple backends to initialize WAL buffers concurrently. This way
`MemSet((char *) NewPage, 0, XLOG_BLCKSZ);` can run in parallel without
taking a single LWLock in exclusive mode.
The new algorithm works as follows:
* reserve a page for initialization using XLogCtl->InitializeReserved,
* ensure the page is written out,
* once the page is initialized, try to advance XLogCtl->InitializedUpTo and
signal to waiters using XLogCtl->InitializedUpToCondVar condition
variable,
* repeat previous steps until we reserve initialization up to the target
WAL position,
* wait until concurrent initialization finishes using a
XLogCtl->InitializedUpToCondVar.
Now, multiple backends can, in parallel, concurrently reserve pages,
initialize them, and advance XLogCtl->InitializedUpTo to point to the latest
initialized page.
Author: Yura Sokolov <y.sokolov@postgrespro.ru>
Co-authored-by: Alexander Korotkov <aekorotkov@gmail.com>
Reviewed-by: Pavel Borisov <pashkin.elfe@gmail.com>
Reviewed-by: Tomas Vondra <tomas@vondra.me>
Tested-by: Michael Paquier <michael@paquier.xyz>
Diffstat (limited to 'src/include')
| -rw-r--r-- | src/include/storage/lwlocklist.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/src/include/storage/lwlocklist.h b/src/include/storage/lwlocklist.h index 932024b1b0b..a9681738146 100644 --- a/src/include/storage/lwlocklist.h +++ b/src/include/storage/lwlocklist.h @@ -37,7 +37,7 @@ PG_LWLOCK(3, XidGen) PG_LWLOCK(4, ProcArray) PG_LWLOCK(5, SInvalRead) PG_LWLOCK(6, SInvalWrite) -PG_LWLOCK(7, WALBufMapping) +/* 7 was WALBufMapping */ PG_LWLOCK(8, WALWrite) PG_LWLOCK(9, ControlFile) /* 10 was CheckpointLock */ |