Re: 2.6.19-rc6-rt8: alsa xruns

Ingo Molnar
2006-11-28T20:11:27Z

* Fernando Lopez-Lezcano <nando@ccrma.Stanford.EDU> wrote:

> Hi, I'm trying out the latest -rt patch and getting alsa xruns when
> using jackd and jack clients. This is a sample from the output of
> qjackctl / jackd (jack 0.102.25, qjackctl 0.2.21):

> ( japa-4096 |#0): new 17 us maximum-latency wakeup.
> ( beagled-3412 |#1): new 19 us maximum-latency wakeup.
> ( IRQ 18-1081 |#1): new 26 us maximum-latency wakeup.
> ( snd-4040 |#1): new 1107 us maximum-latency wakeup.
> ( japa-4096 |#0): new 1445 us maximum-latency wakeup.
> ( japa-4096 |#0): new 2110 us maximum-latency wakeup.
> ( qjackctl-4038 |#1): new 2328 us maximum-latency wakeup.
> ( japa-4096 |#0): new 2548 us maximum-latency wakeup.
> ( IRQ 18-1081 |#0): new 10291 us maximum-latency wakeup.

hm, lets fix this. Could you enable tracing (on the yum rpm) via:

echo 1 > /proc/sys/kernel/trace_enabled

does /proc/latency_trace have any meaningful events included for such a
long delay? If not then it would be nice to rebuild the kernel with
CONFIG_LATENCY_TRACING - and in any case my previous suggestion holds
too: booting with maxcpus=1 to reproduce the latencies will give easier
to interpret latency traces. (but if it's SMP-only then no problem, the
latency traces are still valuable)

Ingo