database/postgres
1
0
Fork 0
mirror of https://github.com/postgres/postgres.git synced 2025-11-03 09:13:20 +03:00
Code Activity

Use LW_SHARED in walsummarizer.c for WALSummarizerLock lock where possible.

Browse Source 
Previously, we used LW_EXCLUSIVE in several places despite only reading
WalSummarizerCtl fields. This patch reduces the lock level to LW_SHARED
where we are only reading the shared fields.

Backpatch to 17, where wal summarization was introduced.

Reviewed-by: Nathan Bossart <nathandbossart@gmail.com>
Discussion: https://postgr.es/m/CAD21AoDdKhf_9oriEYxY-JCdF+Oe_muhca3pcdkMEdBMzyHyKw@mail.gmail.com
Backpatch-through: 17
This commit is contained in:
Masahiko Sawada
2025-08-28 17:06:47 -07:00
parent 456c6a05d9
commit 00064302cb
1 changed files with 2 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
src/backend/postmaster/walsummarizer.c
View File

@@ -641,7 +641,7 @@ SetWalSummarizerLatch(void)
if (WalSummarizerCtl == NULL)
return;
LWLockAcquire(WALSummarizerLock, LW_EXCLUSIVE);
LWLockAcquire(WALSummarizerLock, LW_SHARED);
pgprocno = WalSummarizerCtl->summarizer_pgprocno;
LWLockRelease(WALSummarizerLock);
@@ -682,7 +682,7 @@ WaitForWalSummarization(XLogRecPtr lsn)
/*
* If the LSN summarized on disk has reached the target value, stop.
*/
LWLockAcquire(WALSummarizerLock, LW_EXCLUSIVE);
LWLockAcquire(WALSummarizerLock, LW_SHARED);
summarized_lsn = WalSummarizerCtl->summarized_lsn;
pending_lsn = WalSummarizerCtl->pending_lsn;
LWLockRelease(WALSummarizerLock);