Subject: Re: MultiXact\SLRU buffers configuration

From: Kyotaro Horiguchi <[email-masked]>
Date: Thu, 29 Feb 2024 10:59:44 +0900 (JST)

At Sat, 3 Feb 2024 22:32:45 +0500, "Andrey M. Borodin" <[email-masked]> wrote in 
> Here's the test draft. This test reliably reproduces sleep on CV when waiting next multixact to be filled into "members" SLRU.

By the way, I raised a question about using multiple CVs
simultaneously [1]. That is, I suspect that the current CV
implementation doesn't allow us to use multiple condition variables at
the same time, because all CVs use the same PCPROC member cvWaitLink
to accommodate different waiter sets. If this assumption is correct,
we should resolve the issue before spreading more uses of CVs.

[1] https://www.postgresql.org/message-id/20240227.150709.1766217736683815840.horikyota.ntt%40gmail.com

regards.

-- 
Kyotaro Horiguchi
NTT Open Source Software Center

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From: "Andrey M. Borodin" <[email-masked]>
Date: Sat, 6 Apr 2024 16:24:12 +0500

> On 29 Feb 2024, at 06:59, Kyotaro Horiguchi <[email-masked]> wrote:
> 

Alvaro, Kyotaro, what's our plan for this?
It seems to late to deal with this pg_usleep(1000L) for PG17.
I propose following course of action
1. Close this long-standing CF item
2. Start new thread with CV-sleep patch aimed at PG18
3. Create new entry in July CF

What do you think?

Best regards, Andrey Borodin.