Messages in this thread | | | Date | Mon, 12 Jul 2004 16:31:41 -0700 | From | Andrew Morton <> | Subject | Re: [linux-audio-dev] Re: [announce] [patch] Voluntary Kernel Preemption Patch |
| |
Lee Revell <rlrevell@joe-job.com> wrote: > > On Sun, 2004-07-11 at 01:25, Andrew Morton wrote: > > What we need to do is to encourage audio testers to use ALSA drivers, to > > enable CONFIG_SND_DEBUG in the kernel build and to set > > /proc/asound/*/*/xrun_debug and to send us the traces which result from > > underruns. > > > > OK, here goes. The following traces result from running JACK overnight > like so, on an otherwise idle system. Hardware is a VIA EPIA 6000, with > a 600Mhz C3 processor. Kernel is 2.6.7 + volunatary_preempt patch. > voluntary_preempt and kernel_preemption are both on. > > jackd -v --realtime -d alsa --outchannels 2 --rate 48000 --shorts > --playback --period 32 --nperiods 2 > > These settings require less than 666 microseconds scheduler latency. > The average performance is quite good - 5-20 *microseconds*!
OK, thanks. The problem areas there are the timer-based route cache flushing and reiserfs.
We can probably fix the route caceh thing by rescheduling the timer after having handled 1000 routes or whatever, although I do wonder if this is a thing we really need to bother about - what else was that machine up to?
resierfs: yes, it's a problem. I "fixed" it multiple times in 2.4, but the fixes ended up breaking the fs in subtle ways and I eventually gave up. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |