From 8c8f7b199d9095dbc2e101a4614043b5ae13bde3 Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Wed, 10 Sep 2025 07:23:05 +0900 Subject: [PATCH] Fix leak with SMgrRelations in startup process The startup process does not process shared invalidation messages, only sending them, and never calls AtEOXact_SMgr() which clean up any unpinned SMgrRelations. Hence, it is never able to free SMgrRelations on a periodic basis, bloating its hashtable over time. Like the checkpointer and the bgwriter, this commit takes a conservative approach by freeing periodically SMgrRelations when replaying a checkpoint record, either online or shutdown, so as the startup process has a way to perform a periodic cleanup. Issue caused by 21d9c3ee4ef7, so backpatch down to v17. Author: Jingtang Zhang Reviewed-by: Yuhang Qiu Discussion: https://postgr.es/m/28C687D4-F335-417E-B06C-6612A0BD5A10@gmail.com Backpatch-through: 17 --- src/backend/access/transam/xlog.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c index 7ffb2179151..0baf0ac6160 100644 --- a/src/backend/access/transam/xlog.c +++ b/src/backend/access/transam/xlog.c @@ -8385,6 +8385,14 @@ xlog_redo(XLogReaderState *record) checkPoint.ThisTimeLineID, replayTLI))); RecoveryRestartPoint(&checkPoint, record); + + /* + * After replaying a checkpoint record, free all smgr objects. + * Otherwise we would never do so for dropped relations, as the + * startup does not process shared invalidation messages or call + * AtEOXact_SMgr(). + */ + smgrdestroyall(); } else if (info == XLOG_CHECKPOINT_ONLINE) { @@ -8438,6 +8446,14 @@ xlog_redo(XLogReaderState *record) checkPoint.ThisTimeLineID, replayTLI))); RecoveryRestartPoint(&checkPoint, record); + + /* + * After replaying a checkpoint record, free all smgr objects. + * Otherwise we would never do so for dropped relations, as the + * startup does not process shared invalidation messages or call + * AtEOXact_SMgr(). + */ + smgrdestroyall(); } else if (info == XLOG_OVERWRITE_CONTRECORD) { -- 2.39.5