Horton

Re: Get rid of WALBufMappingLock

Pavel Borisov <pashkin.elfe@gmail.com>

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From: Pavel Borisov <pashkin.elfe@gmail.com>
To: Victor Yegorov <vyegorov@gmail.com>
Cc: Yura Sokolov <y.sokolov@postgrespro.ru>, Alexander Korotkov <aekorotkov@gmail.com>, "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>, Andres Freund <andres@anarazel.de>
Date: 2025-02-17T09:20:09Z
Lists: pgsql-hackers 
Hi, Victor!

On Mon, 17 Feb 2025 at 12:47, Victor Yegorov <vyegorov@gmail.com> wrote:
>
> Hey.
>
> I find “Get rid of WALBufMappingLock" commit message misleading, 'cos Lock it's being replaced by CV, actually.
>
> Should the subject be changed to “Replace WALBufMappingLock with ConditionVariable” instead?

The patch replaces WALBufMappingLock with a lockless algorithm based
on atomic variables and CV. Mentioning only CV in the head is only a
part of implementation. Also, the header should better reflect what is
done on the whole, than the implementation details. So I'd rather see
a header like "Replace WALBufMappingLock by lockless algorithm" or
"Initialize WAL buffers concurrently without using WALBufMappingLock"
or something like that.

Kind regards,
Pavel Borisov
Supabase