Re: Real-Time Preemption, -RT-2.6.10-rc2-mm3-V0.7.31-7

From: Ingo Molnar
Date: Wed Dec 01 2004 - 05:34:17 EST



* Rui Nuno Capela <rncbc@xxxxxxxxx> wrote:

> > if (!(count++ & 1))
> > gettimeofday(0,1);
> > }

> Done that.
>
> New XRUN traces are attached, while running RT-V0.7.31-15 now.
> However, I don't seem to get any notorious difference on the results,
> since previous ones. All latencies traced ca. 26-27 usecs.

ah, found the reason why the trace length didnt improve:

+ { // Trigger off trace every other poll...
+ static unsigned int xruntrace_count = 0;
+ if ((xruntrace_count++ % 1) == 0)
+ gettimeofday(0,1);
+ }

this should either be '& 1' as i originally suggested, or '% 2'. The way
it is right now it will stop the trace every time - i.e. what we had
before.

so please disregard my freerunning suggestionsand try the two-periods
solution first.

Ingo
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