[linux-audio-user] Ardour, Jack, and 2.6 kernels

[Jan Depner]

Reiserfs helps.  If I'm doing serious recording I run blackbox or
fluxbox and kill anything that might give me problems.  These can
include:

killall --quiet --wait --signal KILL autorun
killall --quiet --wait --signal KILL artsd
service amd stop
service portmap stop
service nfs stop
service network stop
service ptal-init stop
service lpd stop
service crond stop
service syslog stop

Set it up in a start and stop script.

Jan


On Thu, 2004-05-27 at 12:16, cv223 at comcast.net wrote:
> So, based on Fernando's and Malcolm's advice, I decided to quit fussing with the 2.6 kernels and stick with the 2.4.23 that I have working to do some recording last night.  The band came over - we were set and ready to go.  I hit 'record' to get an idea of the drum mix (we're submixing to stereo) - 3 seconds in, Ardour stops with an 80ms xrun!  Arrgh!  I sweated through the rest of the evening, fearing another occurence at 3:30 into a 4:00 song.  Fortunately, everything went ok.
> 
> I guess I'm back to trying to figure out what's causing these long xruns, now under the 2.4.23 kernel.
> 
> Do most people shut off non-essential daemons during recording sessions, or do any other tricks?  This is kinda frustrating, as the CPU load seems rather low (< 15% when the xrun happened).  I guess I'll test out reiserfs and even ext2 to see if the filesystem is the culprit.
> 
> Thanks for reading the ramble,
> 
> Joel
> 
> 
> > > I guess my main motivation for trying out the 2.6 kernel is laziness.  
> > > Just build the kernel and get the performance and ALSA without patches 
> > > or compiling extra stuff.  At least, that was _supposed_ to be the way 
> > > it worked!  I'll keep trying the new kernels, but keep the old faithful 
> > > 2.4 kernel around for recording.
> > > 
> > > I'm _still_ curious about what causes the long xruns, though.
> > 
> > New versions of alsa can be compiled with the "--debug=full" option (I
> > don't think the current code in the kernel has that). That will enable
> > you to tweak a proc variable to dump the kernel stack on each xrun, it
> > is something like /proc/asound/card0/pcm0p/xrun_debug (for playback,
> > same for recording in pcm0c). "echo "2">/proc/.../xrun_debug" will turn
> > reporting on. You will get the stack traces in /var/log/messages. 
> > 
> > Not that you will immediately know exactly what has to be done to get it
> > fixed, of course :-)
> > 
> > IMHO stick with 2.4.x, in my tests 2.6.x is not even close to being
> > ready for pro audio work. It will get better but it will take some time.
> > 
> > -- Fernando
> > 
> >