v41-0006-WAL-log-VM-setting-for-empty-pages-in-XLOG_HEAP2.patch
text/x-patch
Filename: v41-0006-WAL-log-VM-setting-for-empty-pages-in-XLOG_HEAP2.patch
Type: text/x-patch
Part: 5
Patch
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Format: format-patch
Series: patch v41-0006
Subject: WAL log VM setting for empty pages in XLOG_HEAP2_PRUNE_VACUUM_SCAN
| File | + | − |
|---|---|---|
| src/backend/access/heap/vacuumlazy.c | 29 | 6 |
From 561637633c1417af7dea0509bbbf55dca3c2fead Mon Sep 17 00:00:00 2001
From: Melanie Plageman <melanieplageman@gmail.com>
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 <melanieplageman@gmail.com>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
Reviewed-by: Andres Freund <andres@anarazel.de>
Reviewed-by: Chao Li <li.evan.chao@gmail.com>
---
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