Re: Hang during smokey posix_cond test w/ cobalt and PREEMPT_RT enabled

On 7/21/2026 10:03 AM, Jan Kiszka wrote:
>> What I'm not so sure about is the following:
>>
>> - is running Xenomai 3 with cobalt on a kernel with PREEMPT_RT
>> supported, i.e. should this work?
>>
> 
> Conceptually, yes. Practically, this combination is very likely
> undertested (e.g. not part of our CI).

Understood. Thanks for the explanation.
>> - is it conceivable that the main thread continues execution in the
>> Linux domain before lostage_task_wakeup got called? Or does this
>> indicate that there's something else wrong with our setup?
>>
>> I've enabled all of the Xenomai, dovetail and PREEMPT_RT debug checks
>> that made sense to me and I'm not getting any errors, but of course I
>> might have missed some useful CONFIG option.
>>
> 
> Did you already compare the event flow you are seeing with a reference
> flow you could generated from qemu-arm64 image of xenomai-images? That
> may help looking for the essential differences.
> 
> Furthermore, you could patch xenomai-image to turn on PREEMPT_RT for
> 6.12 on qemu-arm64 as well and possibly run your test in that setup
> (provided its portable enough).
Thanks, that's a great idea, I haven't thought of that. The test is the 
posix_cond test in smokey, i.e. nothing of our own, so I'd assume it is 
portable.

I'll make sure to give this a try and report back, it just might take a 
couple of days.

Regards,
Dominic