Re: [Xenomai-core] [RFC][PATCH] nucleus: Prevent rescheduling while in xntbase_tick

[Jan Kiszka <jan.kiszka@domain.hid>]

On 2011-06-17 12:58, Gilles Chanteperdrix wrote:
> On 06/17/2011 11:27 AM, Jan Kiszka wrote:
>> Based on code inspection, it looks like a timer handler triggering a
>> reschedule in the path xntbase_tick -> xntimer_tick_aperiodic /
>> xntimer_tick_periodic_inner -> handler can cause problems, e.g. a
>> reschedule before all expired timers were processed. The timer core is
>> usually run atomically from an interrupt handler, so better emulate an
>> IRQ context inside xntbase_tick by setting XNINIRQ.
> 
> I do not understand this one either: if we are inside
> xntimer_tick_aperiodic, XNINIRQ is already set.

Not if you come via xntbase_tick, called by the mentioned skins also
outside a timer IRQ (at least based on my understanding of that skin
APIs). But I might be wrong, I just came across this while checking for
potentially invalid cached xnpod_current_sched values.

Jan

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