From: Alexander Korotkov <akorotkov@postgresql.org>
To: pgsql-committers@lists.postgresql.org
Subject: pgsql: Limit checkpointer requests queue size
Date: Sun, 27 Jul 2025 12:33:03 +0000
Message-ID: <E1ug0Yp-000ysn-22@gemulon.postgresql.org> (raw)
Limit checkpointer requests queue size
If the number of sync requests is big enough, the palloc() call in
AbsorbSyncRequests() will attempt to allocate more than 1 GB of memory,
resulting in failure. This can lead to an infinite loop in the checkpointer
process, as it repeatedly fails to absorb the pending requests.
This commit limits the checkpointer requests queue size to 10M items. In
addition to preventing the palloc() failure, this change helps to avoid long
queue processing time.
Also, this commit is for backpathing only. The master branch receives
a more invasive yet comprehensive fix for this problem.
Discussion: https://postgr.es/m/db4534f83a22a29ab5ee2566ad86ca92%40postgrespro.ru
Backpatch-through: 13
Branch
------
REL_18_STABLE
Details
-------
https://git.postgresql.org/pg/commitdiff/bae50782170c9de8aa13700423923a5bb9d6b9e9
Modified Files
--------------
src/backend/postmaster/checkpointer.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-committers@postgresql.org
Cc: akorotkov@postgresql.org, pgsql-committers@lists.postgresql.org
Subject: Re: pgsql: Limit checkpointer requests queue size
In-Reply-To: <E1ug0Yp-000ysn-22@gemulon.postgresql.org>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox