diff options
Diffstat (limited to 'src/backend/access/transam/xlog.c')
| -rw-r--r-- | src/backend/access/transam/xlog.c | 33 |
1 files changed, 32 insertions, 1 deletions
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 0d494e2e3bf..20c04240b70 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -433,6 +433,11 @@ typedef struct XLogCtlData Latch recoveryWakeupLatch; /* + * WALWriterLatch is used to wake up the WALWriter to write some WAL. + */ + Latch WALWriterLatch; + + /* * During recovery, we keep a copy of the latest checkpoint record here. * Used by the background writer when it wants to create a restartpoint. * @@ -1916,19 +1921,35 @@ XLogWrite(XLogwrtRqst WriteRqst, bool flexible, bool xlog_switch) } /* - * Record the LSN for an asynchronous transaction commit/abort. + * Record the LSN for an asynchronous transaction commit/abort + * and nudge the WALWriter if there is a complete page to write. * (This should not be called for for synchronous commits.) */ void XLogSetAsyncXactLSN(XLogRecPtr asyncXactLSN) { + XLogRecPtr WriteRqstPtr = asyncXactLSN; + /* use volatile pointer to prevent code rearrangement */ volatile XLogCtlData *xlogctl = XLogCtl; SpinLockAcquire(&xlogctl->info_lck); + LogwrtResult = xlogctl->LogwrtResult; if (XLByteLT(xlogctl->asyncXactLSN, asyncXactLSN)) xlogctl->asyncXactLSN = asyncXactLSN; SpinLockRelease(&xlogctl->info_lck); + + /* back off to last completed page boundary */ + WriteRqstPtr.xrecoff -= WriteRqstPtr.xrecoff % XLOG_BLCKSZ; + + /* if we have already flushed that far, we're done */ + if (XLByteLE(WriteRqstPtr, LogwrtResult.Flush)) + return; + + /* + * Nudge the WALWriter if we have a full page of WAL to write. + */ + SetLatch(&XLogCtl->WALWriterLatch); } /* @@ -5072,6 +5093,7 @@ XLOGShmemInit(void) XLogCtl->Insert.currpage = (XLogPageHeader) (XLogCtl->pages); SpinLockInit(&XLogCtl->info_lck); InitSharedLatch(&XLogCtl->recoveryWakeupLatch); + InitSharedLatch(&XLogCtl->WALWriterLatch); /* * If we are not in bootstrap mode, pg_control should already exist. Read @@ -10013,3 +10035,12 @@ WakeupRecovery(void) { SetLatch(&XLogCtl->recoveryWakeupLatch); } + +/* + * Manage the WALWriterLatch + */ +Latch * +WALWriterLatch(void) +{ + return &XLogCtl->WALWriterLatch; +} |