Re: Use LW_SHARED in WakeupWalSummarizer() for WALSummarizerLock lock

From: Masahiko Sawada <sawada(dot)mshk(at)gmail(dot)com>
To: Nathan Bossart <nathandbossart(at)gmail(dot)com>
Cc: PostgreSQL Hackers <pgsql-hackers(at)lists(dot)postgresql(dot)org>
Subject: Re: Use LW_SHARED in WakeupWalSummarizer() for WALSummarizerLock lock
Date: 2025-08-26 00:48:49
Message-ID: CAD21AoBi6_YVdjMupppOuhRq_SBPFYJuiJER+CCcisZWA_ZZcg@mail.gmail.com
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On Mon, Aug 25, 2025 at 5:08 PM Nathan Bossart <nathandbossart(at)gmail(dot)com> wrote:
>
> On Mon, Aug 25, 2025 at 03:38:13PM -0700, Masahiko Sawada wrote:
> > While reading walsummarizer.c code, I noticed that in
> > WakeupWalSummarizer() we acquire the WALSummarizerLock lock in
> > LW_EXCLUSIVE mode despite only reading
> > WalSummarizerCtl->summarizer_pgprocno. The attached patch uses
> > LW_SHARED mode instead. Feedback is very welcome.
>
> You could probably do something similar for WaitForWalSummarization().

Good point. I've attached the updated patch.

Regards,

--
Masahiko Sawada
Amazon Web Services: https://aws.amazon.com

Attachment Content-Type Size
v2-0001-Use-LW_SHARED-in-walsummarizer.c-for-WALSummarize.patch application/octet-stream 1.6 KB

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