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| author | Alexander Korotkov <akorotkov@postgresql.org> | 2024-04-07 00:31:43 +0300 |
|---|---|---|
| committer | Alexander Korotkov <akorotkov@postgresql.org> | 2024-04-07 00:49:53 +0300 |
| commit | 25f42429e2ff2acca35c9154fc2e36b75c79227a (patch) | |
| tree | a007e1ef361c34cef94c12d8e49bb2e3a2966928 /src/backend | |
| parent | 1577081e9614345534a018e788a2c0bab4da4dc5 (diff) | |
| download | postgresql-25f42429e2ff2acca35c9154fc2e36b75c79227a.tar.gz postgresql-25f42429e2ff2acca35c9154fc2e36b75c79227a.zip | |
Use an LWLock instead of a spinlock in waitlsn.c
This should prevent busy-waiting when number of waiting processes is high.
Discussion: https://postgr.es/m/202404030658.hhj3vfxeyhft%40alvherre.pgsql
Author: Alvaro Herrera
Diffstat (limited to 'src/backend')
| -rw-r--r-- | src/backend/commands/waitlsn.c | 15 | ||||
| -rw-r--r-- | src/backend/utils/activity/wait_event_names.txt | 1 |
2 files changed, 8 insertions, 8 deletions
diff --git a/src/backend/commands/waitlsn.c b/src/backend/commands/waitlsn.c index 51a34d422e2..a57b818a2d4 100644 --- a/src/backend/commands/waitlsn.c +++ b/src/backend/commands/waitlsn.c @@ -58,7 +58,6 @@ WaitLSNShmemInit(void) &found); if (!found) { - SpinLockInit(&waitLSN->waitersHeapMutex); pg_atomic_init_u64(&waitLSN->minWaitedLSN, PG_UINT64_MAX); pairingheap_initialize(&waitLSN->waitersHeap, lsn_cmp, NULL); memset(&waitLSN->procInfos, 0, MaxBackends * sizeof(WaitLSNProcInfo)); @@ -115,13 +114,13 @@ addLSNWaiter(XLogRecPtr lsn) procInfo->procnum = MyProcNumber; procInfo->waitLSN = lsn; - SpinLockAcquire(&waitLSN->waitersHeapMutex); + LWLockAcquire(WaitLSNLock, LW_EXCLUSIVE); pairingheap_add(&waitLSN->waitersHeap, &procInfo->phNode); procInfo->inHeap = true; updateMinWaitedLSN(); - SpinLockRelease(&waitLSN->waitersHeapMutex); + LWLockRelease(WaitLSNLock); } /* @@ -132,11 +131,11 @@ deleteLSNWaiter(void) { WaitLSNProcInfo *procInfo = &waitLSN->procInfos[MyProcNumber]; - SpinLockAcquire(&waitLSN->waitersHeapMutex); + LWLockAcquire(WaitLSNLock, LW_EXCLUSIVE); if (!procInfo->inHeap) { - SpinLockRelease(&waitLSN->waitersHeapMutex); + LWLockRelease(WaitLSNLock); return; } @@ -144,7 +143,7 @@ deleteLSNWaiter(void) procInfo->inHeap = false; updateMinWaitedLSN(); - SpinLockRelease(&waitLSN->waitersHeapMutex); + LWLockRelease(WaitLSNLock); } /* @@ -160,7 +159,7 @@ WaitLSNSetLatches(XLogRecPtr currentLSN) wakeUpProcNums = palloc(sizeof(int) * MaxBackends); - SpinLockAcquire(&waitLSN->waitersHeapMutex); + LWLockAcquire(WaitLSNLock, LW_EXCLUSIVE); /* * Iterate the pairing heap of waiting processes till we find LSN not yet @@ -182,7 +181,7 @@ WaitLSNSetLatches(XLogRecPtr currentLSN) updateMinWaitedLSN(); - SpinLockRelease(&waitLSN->waitersHeapMutex); + LWLockRelease(WaitLSNLock); /* * Set latches for processes, whose waited LSNs are already replayed. This diff --git a/src/backend/utils/activity/wait_event_names.txt b/src/backend/utils/activity/wait_event_names.txt index 39a1c40d76c..5f2fa814c8e 100644 --- a/src/backend/utils/activity/wait_event_names.txt +++ b/src/backend/utils/activity/wait_event_names.txt @@ -345,6 +345,7 @@ WALSummarizer "Waiting to read or update WAL summarization state." DSMRegistry "Waiting to read or update the dynamic shared memory registry." InjectionPoint "Waiting to read or update information related to injection points." SerialControl "Waiting to read or update shared <filename>pg_serial</filename> state." +WaitLSN "Waiting to read or update shared Wait-for-LSN state." # # END OF PREDEFINED LWLOCKS (DO NOT CHANGE THIS LINE) |