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

[Fernando Pablo Lopez-Lezcano]

> 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