From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Mon, 15 Dec 2014 15:20:21 +0100
From: Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>
Message-ID: <20141215142021.GL11058@hermes.click-hack.org>
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Subject: Re: [Xenomai] Sleeping function called from invalid context
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To: "Stoidner, Christoph" <c.stoidner@arvero.de>
Cc: "xenomai@xenomai.org" <xenomai@xenomai.org>

On Mon, Dec 15, 2014 at 01:29:19PM +0000, Stoidner, Christoph wrote:
> >> > it seems to me as APC interrupts on ipipe got lost. I have added two counters:
> >> > One increments in schedule_linux_call() when a request for a specific application
> >> > task is queued. Another one is incremented in lostage_handler() when the
> >> > specific task was waked up. When I output the counter's values after tasks have
> >> > freezed the counter of lostage_handler is exactly one value less than
> >> > schedule_linux_call's counter.
> >> >
> >> > And then, when I wake-up APC thread manually all freezed tasks continue for a
> >> > moment, until all are freezing again.
> >>
> >> As said above waking APC thread using
> >>
> >>   wake_up_process(rthal_apc_servers[smp_processor_id()]);
> >>
> >> does reactivate all Xenomai threads for scheduling. Incontrast using
> >>
> >>   rthal_apc_schedule(lostage_apc);
> >>
> >> does not help. So it seems as APC interrupt is pending but won't be  executed.
> >>
> >> Any idea?
> >
> > Do you have the same issue if you run a kernel patched with Xenomai
> > and without the PREEMPT_RT patch?
> 
> No, without PREEMPT_RT the problem did not yet occur.

Have you tried to follow the path from rthal_apc_schedule to
rthal_apc_handler to see where the notification gets lost? 

Also note that calling wake_up_process from primary mode is not a
good idea.

-- 
					    Gilles.