diff options
Diffstat (limited to 'src/backend/access/transam/xlogutils.c')
| -rw-r--r-- | src/backend/access/transam/xlogutils.c | 27 |
1 files changed, 23 insertions, 4 deletions
diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c index a4dedc58b71..bb2d3ec991c 100644 --- a/src/backend/access/transam/xlogutils.c +++ b/src/backend/access/transam/xlogutils.c @@ -22,6 +22,7 @@ #include "access/timeline.h" #include "access/xlogrecovery.h" #include "access/xlog_internal.h" +#include "access/xlogprefetcher.h" #include "access/xlogutils.h" #include "miscadmin.h" #include "pgstat.h" @@ -355,11 +356,13 @@ XLogReadBufferForRedoExtended(XLogReaderState *record, RelFileNode rnode; ForkNumber forknum; BlockNumber blkno; + Buffer prefetch_buffer; Page page; bool zeromode; bool willinit; - if (!XLogRecGetBlockTag(record, block_id, &rnode, &forknum, &blkno)) + if (!XLogRecGetBlockTagExtended(record, block_id, &rnode, &forknum, &blkno, + &prefetch_buffer)) { /* Caller specified a bogus block_id */ elog(PANIC, "failed to locate backup block with ID %d", block_id); @@ -381,7 +384,8 @@ XLogReadBufferForRedoExtended(XLogReaderState *record, { Assert(XLogRecHasBlockImage(record, block_id)); *buf = XLogReadBufferExtended(rnode, forknum, blkno, - get_cleanup_lock ? RBM_ZERO_AND_CLEANUP_LOCK : RBM_ZERO_AND_LOCK); + get_cleanup_lock ? RBM_ZERO_AND_CLEANUP_LOCK : RBM_ZERO_AND_LOCK, + prefetch_buffer); page = BufferGetPage(*buf); if (!RestoreBlockImage(record, block_id, page)) elog(ERROR, "failed to restore block image"); @@ -410,7 +414,7 @@ XLogReadBufferForRedoExtended(XLogReaderState *record, } else { - *buf = XLogReadBufferExtended(rnode, forknum, blkno, mode); + *buf = XLogReadBufferExtended(rnode, forknum, blkno, mode, prefetch_buffer); if (BufferIsValid(*buf)) { if (mode != RBM_ZERO_AND_LOCK && mode != RBM_ZERO_AND_CLEANUP_LOCK) @@ -450,6 +454,10 @@ XLogReadBufferForRedoExtended(XLogReaderState *record, * exist, and we don't check for all-zeroes. Thus, no log entry is made * to imply that the page should be dropped or truncated later. * + * Optionally, recent_buffer can be used to provide a hint about the location + * of the page in the buffer pool; it does not have to be correct, but avoids + * a buffer mapping table probe if it is. + * * NB: A redo function should normally not call this directly. To get a page * to modify, use XLogReadBufferForRedoExtended instead. It is important that * all pages modified by a WAL record are registered in the WAL records, or @@ -457,7 +465,8 @@ XLogReadBufferForRedoExtended(XLogReaderState *record, */ Buffer XLogReadBufferExtended(RelFileNode rnode, ForkNumber forknum, - BlockNumber blkno, ReadBufferMode mode) + BlockNumber blkno, ReadBufferMode mode, + Buffer recent_buffer) { BlockNumber lastblock; Buffer buffer; @@ -465,6 +474,15 @@ XLogReadBufferExtended(RelFileNode rnode, ForkNumber forknum, Assert(blkno != P_NEW); + /* Do we have a clue where the buffer might be already? */ + if (BufferIsValid(recent_buffer) && + mode == RBM_NORMAL && + ReadRecentBuffer(rnode, forknum, blkno, recent_buffer)) + { + buffer = recent_buffer; + goto recent_buffer_fast_path; + } + /* Open the relation at smgr level */ smgr = smgropen(rnode, InvalidBackendId); @@ -523,6 +541,7 @@ XLogReadBufferExtended(RelFileNode rnode, ForkNumber forknum, } } +recent_buffer_fast_path: if (mode == RBM_NORMAL) { /* check that page has been initialized */ |