[Xenomai-core] Re: SVN checkin #2010

[Philippe Gerum <rpm@xenomai.org>]

On Tue, 2007-01-02 at 14:30 +0100, Gilles Chanteperdrix wrote:
> Philippe Gerum wrote:
> > On Tue, 2007-01-02 at 11:20 +0100, Jan Kiszka wrote:
> > 
> >>Hi all - and happy new year,
> >>
> >>I haven't looked at all the new code yet, only the commit messages. I
> >>found something similar to my fast-forward-on-timer-overrun patch in
> >>#2010 and wondered if Gilles' original concerns on side effects for the
> >>POSIX skin were addressed [1]. I recalled that my own final summary on
> >>this was "leave it as it is" [2].
> >>
> > 
> > 
> > The best approach is to update the POSIX skin so that it does not rely
> > on the timer code to act in a sub-optimal way; that's why this patch
> > found its way in. Scheduling and processing timer shots uselessly is a
> > bug, not a feature in this case.
> 
> There is some work to be done on the posix skin anyway, this will all be
> at once. By the way, I tested the trunk on ARM, and I still get a lockup
> when the latency period is too low. I wonder if we should not compare to
> "now + nkschedlat", or even use xnarch_get_cpu_tsc() instead of "now".

You mean as below, in order to account for the time spent in the handler(s)?	

-	while ((xntimerh_date(&timer->aplink) += timer->interval) < now)
+	while ((xntimerh_date(&timer->aplink) += timer->interval) < xnarch_get_cpu_tsc())
		    ;

-- 
Philippe.