Re: lockup in parallel hash join on dikkop (freebsd 14.0-current)

[Tomas Vondra]

On 2/6/23 20:20, Andres Freund wrote:
> 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.
> 

No, I left the workload as it was for the first lockup, so `make check`
runs everything as is up until the "join" test suite.

regards

-- 
Tomas Vondra
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