21 Jan
2004
21 Jan
'04
7:44 a.m.
On Wed, 21 Jan 2004 11:15:11 +0000
Steve Harris <S.W.Harris(a)ecs.soton.ac.uk> wrote:
I usually use 4 or 8 pretty large periods of 512 frames [my soundcard
doesn't allow larger one]. On linux 2.4.22 [LL+preempt+cap patch] i can
get very stable performance. I can even compile a kernel in the
background and get no xruns [except for an occasional one]. I tested the
2.6.0 kernel and it was much more touchy. Start using the disk and xruns
occur right and left. I will try the 2.6.1 today though..
I don't know though if i configured the 2.6 kernel right [preemptible,
etc..]
I once took a look at the latency measuring tools, but i could not
really make sense out of them [not being a kernel hacker]. So i suppose
testing would be much easier, if there was a little tool, which everyone
could just run and it would do some testing which we could then report
back to andrew..
Flo
--
http://www.soundclick.com/bands/9/florianschmidt.htm
http://www.arted.biz/mista.tapas
I don't
know what these numbers mean...
What does this transalate to in interval-in-milliseconds, and after
how many milliseconds delay will an underrun occur?
The default sampe rate is 48kHz, so 1024 samples/block gives 21ms
between interupts. Jack easts a bit of that, but you'd have ~20ms
before an underrun occured.
And what else is happening on the system at the
time?
The original poster would have to anwer that. Jack itsself is just
messing with SYSV SHM and occasioanly touching fifos.
As someone else said, jack runs reliably on most 2.4+ll+o(1)sched
systems with 5ms (256 sample) interupt fequencies and usually lower.