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From: Philippe Gerum <rpm@xenomai.org>
To: Russell Johnson <russell.johnson@kratosdefense.com>
Cc: Bryan Butler <Bryan.Butler@kratosdefense.com>, "xenomai@lists.linux.dev"
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Subject: Re: [External] - Re: System hanging when using condition variables
Date: Wed, 28 Sep 2022 11:59:03 +0200
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Russell Johnson <russell.johnson@kratosdefense.com> writes:

> [[S/MIME Signed Part:Undecided]]
> I am not sure if this is useful in the meantime but I have attached the
> kernel stack traces that we see whenever a  CPU gets stuck.
>
> Thanks,
>
> Russell
>
> [2. text/plain; stacktrace_1.txt]...
>
> [3. text/plain; stacktrace_2.txt]...
>
> [[End of S/MIME Signed Part]]

We see a NMI hitting a place where the CPU seems to attempt to grab a
lock, so this would indeed point the finger at a locking issue once
again.

Could you enable CONFIG_PROVE_LOCKING, CONFIG_EXPERT then
CONFIG_DEBUG_HARD_LOCKS for testing? Maybe lockdep is going to help us
(this will wreck the timings with a significant slowdown, hopefully the
app can still run in a degraded mode in that case).

-- 
Philippe.