Re: [Xenomai-core] [RFC] Fix excessive host tick latencies

[Gilles Chanteperdrix <gilles.chanteperdrix@xenomai.org>]

Philippe Gerum wrote:
> On Fri, 2010-04-30 at 15:33 +0200, Jan Kiszka wrote:
>> Hi Philippe,
>>
>> I'm not 100% sure if this plugs all remaining wholes in the deferred
>> host tick processing, but at least the most easiest reproducible one is
>> cured now for me (Linux latency peak after termination of 'latency').
>> Please let me know if you see more potential issues, otherwise I would
>> include this in my for-upstream queue.
> 
> That patch is correct, please queue it. Anything that breaks the
> assumption described in the following comment from
> xntimer_next_local_shot() is wrong wrt tick deferral: "The host tick
> deferral is cleared whenever Xenomai is about to yield control to the
> host kernel".
> 
> In short, when the code will match the comments and documentation, we
> will be done with debugging.

What I meant is that with the nucleus debugging fixed, we may not even
enter __xnpod_schedule often enough to handle the host tick propagation.
So, maybe we should make xnpod_schedule call __xnpod_schedule if XNHTICK
or XNHDEFER are set.

-- 
					    Gilles.