public inbox for [email protected]  
help / color / mirror / Atom feed
From: Pavel Borisov <[email protected]>
To: Maxim Orlov <[email protected]>
Cc: Alexander Korotkov <[email protected]>
Cc: wenhui qiu <[email protected]>
Cc: Heikki Linnakangas <[email protected]>
Cc: Postgres hackers <[email protected]>
Subject: Re: POC: make mxidoff 64 bits
Date: Thu, 12 Sep 2024 16:25:53 +0400
Message-ID: <CALT9ZEG4OoQk8OUBCNY8cT3GuUvcQ0NrphHZ9H8--VjwM5VWUw@mail.gmail.com> (raw)
In-Reply-To: <CALT9ZEHm138m2rTi6-N_Xcm0ibfbK0b7yysdPHj1v144YUOFQg@mail.gmail.com>
References: <CACG=ezaWg7_nt-8ey4aKv2w9LcuLthHknwCawmBgEeTnJrJTcw@mail.gmail.com>
	<[email protected]>
	<CAGjGUAKO1GCzG5wBMt5RosWo0PatgFpYY=Gjgt77tN2brNe=Bg@mail.gmail.com>
	<CACG=ezYokoiumOFnqUfg_ffHD5s8T+6iHYfzKLfa=QQ-1pNrBg@mail.gmail.com>
	<CACG=ezY9xq73jcX_EjVqx5-f90nbQ9PyhFCTW2fwFCS2wmNiFw@mail.gmail.com>
	<CACG=eza+27CfLBobJJccRhXrA3He6c1irAnoyTtSC1-z9UXLrg@mail.gmail.com>
	<CAPpHfduczcop9s6gKUpLGgFUe2y4ERGMJx6SS6Kp+s-kQPwMjg@mail.gmail.com>
	<CACG=ezbye4g_ERNqE=gBcvQ0YypRaVENhNUu8xrs4PL12UdnUA@mail.gmail.com>
	<CACG=ezaMncd0-BcGHBgsSR2eqHfrz9WznHGLKX8biz6zu-azGw@mail.gmail.com>
	<CALT9ZEHm138m2rTi6-N_Xcm0ibfbK0b7yysdPHj1v144YUOFQg@mail.gmail.com>

On Thu, 12 Sept 2024 at 16:09, Pavel Borisov <[email protected]> wrote:

> Hi, Maxim!
>
> Previously we accessed offsets in shared MultiXactState without locks as
> 32-bit read is always atomic. But I'm not sure it's so when offset become
> 64-bit.
> E.g. GetNewMultiXactId():
>
> nextOffset = MultiXactState->nextOffset;
> is outside lock.
>
> There might be other places we do the same as well.
>
I think the replacement of plain assignments by
pg_atomic_read_u64/pg_atomic_write_u64 would be sufficient.

(The same I think is needed for the patchset [1])
[1]
https://www.postgresql.org/message-id/flat/CAJ7c6TMvPz8q+nC=JoKniy7yxPzQYcCTnNFYmsDP-nnWsAOJ2g@mail....

Regards,
Pavel Borisov


view thread (21+ messages)  latest in thread

reply

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: [email protected]
  Cc: [email protected], [email protected], [email protected], [email protected], [email protected], [email protected]
  Subject: Re: POC: make mxidoff 64 bits
  In-Reply-To: <CALT9ZEG4OoQk8OUBCNY8cT3GuUvcQ0NrphHZ9H8--VjwM5VWUw@mail.gmail.com>

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

This inbox is served by agora; see mirroring instructions
for how to clone and mirror all data and code used for this inbox