Messages in this thread | | | Subject | Re: 2.6.19-rc6-rt8: alsa xruns | From | Fernando Lopez-Lezcano <> | Date | Tue, 28 Nov 2006 13:35:55 -0800 |
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On Tue, 2006-11-28 at 13:04 -0800, Fernando Lopez-Lezcano wrote: > On Tue, 2006-11-28 at 12:37 -0800, Fernando Lopez-Lezcano wrote: > > On Tue, 2006-11-28 at 21:09 +0100, Ingo Molnar wrote: > > > * 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. > > > > Sorry, it looks like it is an smp issue. Booting with maxcpus=1 reduces > > the xrun reports significantly (only three so far but very short, in the > > range of 0.029 to 0.041 ms). The long ones seem to have gone away, so > > far... > > Strange, I rebooted smp and I'm not seeing the very long xruns I was > seeing before, only short ones as reported above. Here are some traces, > but nothing that makes sense I think. > > I'll turn off the machine and cold boot it...)
No difference, actually it looks like the regression re-regresses if I enable the trace... Arghhh.
Toggling /proc/sys/kernel/trace_enabled makes the long xruns reported by jack come and go.
-- Fernando
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