Re: fc2, xorg, 2.6.x, scheduling latency peaks

[Fernando Pablo Lopez-Lezcano <nando ccrma Stanford EDU>]

On Wed, 2004-06-02 at 00:32, Arjan van de Ven wrote:
> > a) 2.6.6-1.391 with preempt on:
> > http://ccrma.stanford.edu/~nando/latencytest/20040601/2.6.6-1.391.1.ll.rhfc2.ccrma/
> 
> 85.8% is in the 1ms range
> > 
> > b) 2.6.6-1.391 with preempt off:
> > http://ccrma.stanford.edu/~nando/latencytest/20040601/2.6.6-1.391.2.ll.rhfc2.ccrma/
> 
> 87.9% is in the 1ms range
> 
> so somewhat better

I guess beauty is in the eyes of the beholder :-) More peaks are within
the 1ms range _but_ the actual peaks that get through are larger without
preempt. The smaller the peaks the smaller the risk that an actual xrun
will happen (more "slack"). Regretfully it takes just one xrun to get an
audible click in the audio output. 

> > c) 2.6.6-1.391 with preempt off and bad radeon latency patch (see
> > comments below):
> > http://ccrma.stanford.edu/~nando/latencytest/20040601/2.6.6-1.391.3.ll.rhfc2.ccrma/
>
> ohhh interesting
> 
> I will be looking at the patch and see if I can fix it up.. the results
> look spiffy.

They do. More comments in the next email.
-- Fernando