Re: Non-reproducible AIO failure

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: Andres Freund <andres(at)anarazel(dot)de>
Cc: Konstantin Knizhnik <knizhnik(at)garret(dot)ru>, pgsql-hackers(at)lists(dot)postgresql(dot)org
Subject: Re: Non-reproducible AIO failure
Date: 2025-06-08 19:15:43
Message-ID: 221229.1749410143@sss.pgh.pa.us
Views: Whole Thread | Raw Message | Download mbox | Resend email
Thread:
Lists: pgsql-hackers

Andres Freund <andres(at)anarazel(dot)de> writes:
> The symptoms I can reproduce are slightly different than Alexander's - it's
> the assertion failure reported upthread by Tom.
>
> FWIW, I can continue to repro the assertion after removing the use of the
> bitfield in PgAioHandle. So the problem indeed seems to be be independent of
> the bitfields.

I noticed that the assertion you and I are seeing is also about
a bitfield:

TRAP: failed Assert("aio_ret->result.status != PGAIO_RS_UNKNOWN"), File: "bufmgr.c", Line: 1605, PID: 79322

typedef struct PgAioResult
{
...
/* of type PgAioResultStatus, see above */
uint32 status:PGAIO_RESULT_STATUS_BITS;
...
} PgAioResult;

That doesn't make a lot of sense to me, because as far as I've
seen the bitfields in PgAioResult are not concurrently accessed.
But it feels like a relevant observation.

regards, tom lane

In response to

Browse pgsql-hackers by date

  From Date Subject
Next Message Pavel Stehule 2025-06-08 20:11:26 Re: Sanding down some edge cases for PL/pgSQL reserved words
Previous Message Pavel Stehule 2025-06-08 19:00:48 Re: pg_restore - cannot to restore blobs in dictionary format from older pg dumps