Re: Issue with the PRNG used by Postgres - Mailing list pgsql-hackers

From Andres Freund
Subject Re: Issue with the PRNG used by Postgres
Date
Msg-id 20240409210521.dwcjdobnwkyjbars@awork3.anarazel.de
Whole thread Raw
In response to [MASSMAIL]Issue with the PRNG used by Postgres  (Parag Paul <parag.paul@gmail.com>)
Responses Re: Issue with the PRNG used by Postgres  (Robert Haas <robertmhaas@gmail.com>)
Re: Issue with the PRNG used by Postgres  (Parag Paul <parag.paul@gmail.com>)
List pgsql-hackers
Hi,

On 2024-04-08 22:52:09 -0700, Parag Paul wrote:
>  We have an interesting problem, where PG went to PANIC due to stuck
> spinlock case.
> On careful analysis and hours of trying to reproduce this(something that
> showed up in production after almost 2 weeks of stress run), I did some
> statistical analysis on the RNG generator that PG uses to create the
> backoff for the spin locks.

ISTM that the fix here is to not use a spinlock for whatever the contention is
on, rather than improve the RNG.

Greetings,

Andres Freund



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