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| author | Noah Misch <noah@leadboat.com> | 2024-10-29 09:39:55 -0700 |
|---|---|---|
| committer | Noah Misch <noah@leadboat.com> | 2024-10-29 09:39:55 -0700 |
| commit | 30d47ec8c6c78f46bcd7116b7effb6988b126e43 (patch) | |
| tree | 6923495c5c6d211a84d4edda9219eb649c0d6ac4 /src/backend/access/index/genam.c | |
| parent | 502e7bf7f09c458ce66ce043b94864b535c5d5d0 (diff) | |
| download | postgresql-30d47ec8c6c78f46bcd7116b7effb6988b126e43.tar.gz postgresql-30d47ec8c6c78f46bcd7116b7effb6988b126e43.zip | |
Unpin buffer before inplace update waits for an XID to end.
Commit a07e03fd8fa7daf4d1356f7cb501ffe784ea6257 changed inplace updates
to wait for heap_update() commands like GRANT TABLE and GRANT DATABASE.
By keeping the pin during that wait, a sequence of autovacuum workers
and an uncommitted GRANT starved one foreground LockBufferForCleanup()
for six minutes, on buildfarm member sarus. Prevent, at the cost of a
bit of complexity. Back-patch to v12, like the earlier commit. That
commit and heap_inplace_lock() have not yet appeared in any release.
Discussion: https://postgr.es/m/20241026184936.ae.nmisch@google.com
Diffstat (limited to 'src/backend/access/index/genam.c')
| -rw-r--r-- | src/backend/access/index/genam.c | 12 |
1 files changed, 5 insertions, 7 deletions
diff --git a/src/backend/access/index/genam.c b/src/backend/access/index/genam.c index 69c36084321..60c61039d66 100644 --- a/src/backend/access/index/genam.c +++ b/src/backend/access/index/genam.c @@ -814,6 +814,7 @@ systable_inplace_update_begin(Relation relation, int retries = 0; SysScanDesc scan; HeapTuple oldtup; + BufferHeapTupleTableSlot *bslot; /* * For now, we don't allow parallel updates. Unlike a regular update, @@ -835,10 +836,9 @@ systable_inplace_update_begin(Relation relation, Assert(IsInplaceUpdateRelation(relation) || !IsSystemRelation(relation)); /* Loop for an exclusive-locked buffer of a non-updated tuple. */ - for (;;) + do { TupleTableSlot *slot; - BufferHeapTupleTableSlot *bslot; CHECK_FOR_INTERRUPTS(); @@ -864,11 +864,9 @@ systable_inplace_update_begin(Relation relation, slot = scan->slot; Assert(TTS_IS_BUFFERTUPLE(slot)); bslot = (BufferHeapTupleTableSlot *) slot; - if (heap_inplace_lock(scan->heap_rel, - bslot->base.tuple, bslot->buffer)) - break; - systable_endscan(scan); - }; + } while (!heap_inplace_lock(scan->heap_rel, + bslot->base.tuple, bslot->buffer, + (void (*) (void *)) systable_endscan, scan)); *oldtupcopy = heap_copytuple(oldtup); *state = scan; |