From bb6a65580687d8bb932e2dc26c32e72025d34354 Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Mon, 24 Oct 2022 12:28:06 -0700 Subject: [PATCH v2 02/14] hio: Release extension lock before initializing page / pinning VM PageInit() while holding the extension lock is unnecessary after 0d1fe9f74e3 started to use RBM_ZERO_AND_LOCK - nobody can look at the new page before we release the page lock. PageInit() zeroes the page, which isn't that cheap, so deferring it until after the extension lock is released seems like a good idea. Doing visibilitymap_pin() while holding the extension lock, introduced in 7db0cd2145f2, looks like an accident. Due to the restrictions on HEAP_INSERT_FROZEN it's unlikely to be a performance issue, but it still seems better to move it out. --- src/backend/access/heap/hio.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/src/backend/access/heap/hio.c b/src/backend/access/heap/hio.c index e152807d2dc..7479212d4e0 100644 --- a/src/backend/access/heap/hio.c +++ b/src/backend/access/heap/hio.c @@ -623,6 +623,13 @@ loop: */ buffer = ReadBufferBI(relation, P_NEW, RBM_ZERO_AND_LOCK, bistate); + /* + * Release the file-extension lock; it's now OK for someone else to extend + * the relation some more. + */ + if (needLock) + UnlockRelationForExtension(relation, ExclusiveLock); + /* * We need to initialize the empty new page. Double-check that it really * is empty (this should never happen, but if it does we don't want to @@ -647,13 +654,6 @@ loop: visibilitymap_pin(relation, BufferGetBlockNumber(buffer), vmbuffer); } - /* - * Release the file-extension lock; it's now OK for someone else to extend - * the relation some more. - */ - if (needLock) - UnlockRelationForExtension(relation, ExclusiveLock); - /* * Lock the other buffer. It's guaranteed to be of a lower page number * than the new page. To conform with the deadlock prevent rules, we ought -- 2.38.0