Sound performance problems in FreeBSD
ssouhlal at FreeBSD.org
Wed Sep 8 23:48:04 PDT 2004
On Sep 5, 2004, at 5:56 AM, Markus Hästbacka wrote:
> Hello list, I've experienced sound performance issues from the very
> first day I tested 5.x. The problem was that sound skipped whatever I
> did. Now I've reduced the problem a bit with changing my kernel config
> (No, any debug option isn't on or haven't ever been on when I've
> tested sound performance). After I recompiled the new kernel the sound
> didn't skip anymore, but now after 10 hour uptime and 5 hours of mp3
> playing the skipping is back. The skipping is like every second
> there's a weird noise if I listen to something, like the track would
> go slower for 2/10 seconds of every second, you can imagine how
> annoying this can be.
FYI, after a few IRC discussions with Markus, we've discovered that
turning off the memory part of Gnome's System Monitor applet, would get
rid of the skips. I believe the problem is that both sysctl and the
sound drivers are Giant-locked, and so there is some contention. An
easy way to reproduce these skips is to run `while true; do sysctl
vm.vmtotal; done`, while playing an mp3.
So, it would be nice to have giant-free sysctl and/or sound drivers..
Suleiman Souhlal | ssouhlal at vt.edu
The FreeBSD Project | ssouhlal at FreeBSD.org
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