MIME-Version: 1.0
From: JoongHyuk Shin <sjh910805@gmail.com>
Date: Sun, 19 Apr 2026 14:46:57 +0900
Message-ID: 
 <CACSdjfO3ox8i8N3KxGf3HThzX1vnRRkY2kq1m5qsvGxjcuM1jg@mail.gmail.com>
Subject: [PATCH] Prevent repeated deadlock-check signals in standby buffer pin
 waits
To: "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>
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In ResolveRecoveryConflictWithBufferPin(), when deadlock_timeout fires,
the function sends RECOVERY_CONFLICT_BUFFERPIN_DEADLOCK and returns.
The caller (LockBufferForCleanup) loops back, sets up another
deadlock_timeout,
and the signal gets sent again every interval.

The lock-conflict path had the same problem and was fixed in 8900b5a9d59a
by adding a second ProcWaitForSignal() after the deadlock-check signal.
The buffer-pin path was left with an XXX comment asking "should we fix
this?".

The attached patch applies the same fix: after sending the deadlock-check
signal, reset got_standby_deadlock_timeout and call ProcWaitForSignal()
so the startup process waits for UnpinBuffer() rather than looping
and re-signaling.

Patch attached.

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<div dir=3D"ltr">In ResolveRecoveryConflictWithBufferPin(), when deadlock_t=
imeout fires,<br>the function sends RECOVERY_CONFLICT_BUFFERPIN_DEADLOCK an=
d returns.<br>The caller (LockBufferForCleanup) loops back, sets up another=
 deadlock_timeout,<br>and the signal gets sent again every interval.<br><br=
>The lock-conflict path had the same problem and was fixed in 8900b5a9d59a<=
br>by adding a second ProcWaitForSignal() after the deadlock-check signal.<=
br>The buffer-pin path was left with an XXX comment asking &quot;should we =
fix this?&quot;.<br><br>The attached patch applies the same fix: after send=
ing the deadlock-check<br>signal, reset got_standby_deadlock_timeout and ca=
ll ProcWaitForSignal()<br>so the startup process waits for UnpinBuffer() ra=
ther than looping<br>and re-signaling.<br><br>Patch attached.</div>

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