On Tue, 2006-11-28 at 21:09 +0100, Ingo Molnar wrote: > * Fernando Lopez-Lezcano <[EMAIL PROTECTED]> 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... > (but if it's SMP-only then no problem, the > latency traces are still valuable) -- Fernando - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
