Re: lockup in parallel hash join on dikkop (freebsd 14.0-current) - Mailing list pgsql-hackers

From Andres Freund
Subject Re: lockup in parallel hash join on dikkop (freebsd 14.0-current)
Date
Msg-id 20230206192015.yhztexkn2eyp3n4q@awork3.anarazel.de
Whole thread Raw
In response to Re: lockup in parallel hash join on dikkop (freebsd 14.0-current)  (Tomas Vondra <tomas.vondra@enterprisedb.com>)
Responses Re: lockup in parallel hash join on dikkop (freebsd 14.0-current)
List pgsql-hackers
Hi,

On 2023-02-06 19:51:19 +0100, Tomas Vondra wrote:
> > No. The only thing the machine is doing is
> > 
> >   while /usr/bin/true; do
> >     make check
> >   done
> > 
> > I can't reduce the workload further, because the "join" test is in a
> > separate parallel group (I cut down parallel_schedule). I could make the
> > machine busier, of course.
> > 
> > However, the other lockup I saw was when using serial_schedule, so I
> > guess lower concurrency makes it more likely.
> > 
> 
> FWIW the machine is now on run ~2700 without any further lockups :-/
> 
> Seems it was quite lucky we hit it twice in a handful of attempts.

Did you cut down the workload before you reproduced it the first time, or
after? It's quite possible that it's not reproducible in isolation.

Greetings,

Andres Freund



pgsql-hackers by date:

Previous
From: Andres Freund
Date:
Subject: Re: Non-superuser subscription owners
Next
From: Thomas Munro
Date:
Subject: Re: GUCs to control abbreviated sort keys