2 Oct
2004
2 Oct
'04
7:33 p.m.
On Sat, 02 Oct 2004 16:58:57 -0400
Lee Revell <rlrevell(a)joe-job.com> wrote:
Hey,
I have been helping this user get set up with 2.6+VP, and it really
looks like the kernel is not the problem - the maximum latency
reported by Ingo's tracer is under 200 usecs, but there are still
xruns. All my tests show that it should work at 128 or even 64 frames
with this setup. It really looks like jackd or the jack clients are
the problem.
One could rule this out by writing a minimal alsa app which does nothing
but writing/reading from an alsa device. Make it sched_fifo, mlock its
memory, and register the alsa xrun callback [if such a thing exists, i
know very little alsa_pcm programming]. Then see if it experiences
xruns, too. If not, then jackd is probably to blame.
Also maybe the alsa drivers themselfes might be problematic/buggy. If
the above minimal alsa app still produces xruns, then either alsa lib or
the drivers themselfes are to blame [probably].
Of course such a test is not a proof but might give important clues.
flo