[linux-audio-user] Graphics card an realtime performance

Lee Revell rlrevell at joe-job.com
Sat Feb 11 14:26:48 EST 2006


On Sat, 2006-02-11 at 16:18 +0100, Gerrit Niestijl wrote:
> > The only reliable way to debug this stuff is with the latency tracer
> > (see the list archives for details).
> 
> Here is a latency trace. I started sooperlooper with it's gui and loaded
> a loop. After a fem minutes some xruns occur that throw sooperlooper out
> of jack. The trace is from immediately after this. Does this reveal
> anything?
> 
> gerrit
> 
> 
> preemption latency trace v1.1.5 on 2.6.14-rt22-debugy
> --------------------------------------------------------------------
>  latency: 89 us, #64/64, CPU#0 | (M:rt VP:0, KP:0, SP:1 HP:1)

Your maximum kernel-induced latency is less than 0.1ms - this
demonstrates that the problem is in one of your apps, not the kernel.
Probably Sooperlooper does something that's not RT safe in it's
process() callback.

In order to find the bug in your JACK clients you can use the "user
triggered latency tracing" feature of the -rt kernel (see list archive).

Lee




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