From 561637633c1417af7dea0509bbbf55dca3c2fead Mon Sep 17 00:00:00 2001 From: Melanie Plageman Date: Sat, 27 Sep 2025 11:55:21 -0400 Subject: [PATCH v41 06/12] WAL log VM setting for empty pages in XLOG_HEAP2_PRUNE_VACUUM_SCAN As part of removing XLOG_HEAP2_VISIBLE records, phase I of VACUUM now marks empty pages all-visible in a XLOG_HEAP2_PRUNE_VACUUM_SCAN record. This has no independent benefit, but empty pages were the last user of XLOG_HEAP2_VISIBLE, so if we make this change we can remove all of the XLOH_HEAP2_VISIBLE code. Author: Melanie Plageman Reviewed-by: Robert Haas Reviewed-by: Andres Freund Reviewed-by: Chao Li --- src/backend/access/heap/vacuumlazy.c | 35 +++++++++++++++++++++++----- 1 file changed, 29 insertions(+), 6 deletions(-) diff --git a/src/backend/access/heap/vacuumlazy.c b/src/backend/access/heap/vacuumlazy.c index d144e0f642b..de93bff4a8e 100644 --- a/src/backend/access/heap/vacuumlazy.c +++ b/src/backend/access/heap/vacuumlazy.c @@ -1928,9 +1928,12 @@ lazy_scan_new_or_empty(LVRelState *vacrel, Buffer buf, BlockNumber blkno, */ if (!PageIsAllVisible(page)) { + /* Lock vmbuffer before entering critical section */ + LockBuffer(vmbuffer, BUFFER_LOCK_EXCLUSIVE); + START_CRIT_SECTION(); - /* mark buffer dirty before writing a WAL record */ + /* Mark buffer dirty before writing any WAL records */ MarkBufferDirty(buf); /* @@ -1948,13 +1951,33 @@ lazy_scan_new_or_empty(LVRelState *vacrel, Buffer buf, BlockNumber blkno, PageSetAllVisible(page); PageClearPrunable(page); - visibilitymap_set(vacrel->rel, blkno, buf, - InvalidXLogRecPtr, - vmbuffer, InvalidTransactionId, - VISIBILITYMAP_ALL_VISIBLE | - VISIBILITYMAP_ALL_FROZEN); + visibilitymap_set_vmbits(blkno, + vmbuffer, + VISIBILITYMAP_ALL_VISIBLE | + VISIBILITYMAP_ALL_FROZEN, + vacrel->rel->rd_locator); + + /* + * Emit WAL for setting PD_ALL_VISIBLE on the heap page and + * setting the VM. + */ + if (RelationNeedsWAL(vacrel->rel)) + log_heap_prune_and_freeze(vacrel->rel, buf, + vmbuffer, + VISIBILITYMAP_ALL_VISIBLE | + VISIBILITYMAP_ALL_FROZEN, + InvalidTransactionId, /* conflict xid */ + false, /* cleanup lock */ + PRUNE_VACUUM_SCAN, /* reason */ + NULL, 0, + NULL, 0, + NULL, 0, + NULL, 0); + END_CRIT_SECTION(); + LockBuffer(vmbuffer, BUFFER_LOCK_UNLOCK); + /* Count the newly all-frozen pages for logging */ vacrel->new_all_visible_pages++; vacrel->new_all_visible_all_frozen_pages++; -- 2.43.0