diagnostic tools to trace the reason xruns are happening?

[Ralf Mardorf]

On Sun, 2011-06-05 at 11:44 +0200, bart deruyter wrote:
> Ok, I did some tests, xruns keep happening on 512 Frames/Period and
> 1024 Frames/Period at 48000, setting Periods/Buffer at 2. At 3
> Periods/Buffer there is too much latency in my opinion.
> 
> Next step, how do I change the governer from 'ondemand' to
> 'performance'? I've never done that before, didn't even need to do
> that in the previous ubuntustudio versions.

You can run

sudo -i
cpufreq-selector -g performance

The better choice is to

right click to the GNOME panel > Add to panel... > CPU frequency scaling
monitor

Once it is in the panel, left click to the scaling monitor icon and
chose 'performance'.


> 
> About the kernel :
> Weird, I keep reading from ubuntustudio that the generic kernel in
> Ubuntustuido 11.04 should be good enough, on the wiki with the
> comparing table I read better results from the lowlatency kernel.. and
> now there is the need for the preempt rt.... It is getting very, very,
> very confusing for me. 
> 
> but thanks for the help of course.. step by step, we'll get there.. we
> just have to.

For kernels before version 2.6.39 and this version isn't supported by
any repository jet, real-time optimisation only is done with kernel-rt.
A kernel without RT can work too, but when you get issues, then use a
kernel-rt.

Hth,

Ralf