Re: ardour crashes when jack uses /tmp/jack

On Fri, 31 Oct 2003 22:39:11 -0500
Paul Davis <paul <at> linuxaudiosystems.com> wrote:

> don't be too sure of this. we discovered a bug in JACK. although in
> notifies clients of xruns, it doesn't tell you about them all the
> time.
> 

I had qjackctl running and was monitoring the messages window from time
to time. qjackctl as a jack client should get notified, too?

Interesting enough though that with large buffers [32 periods a 512
frames] there seems to be no correlation of system load and eventual
xruns. Right now i'm compiling a kernel, having ardour playback 4 tracks
and have some stuff in jack-rack and no xruns in either the message
window of qjackctl nor the term that i started ardour with....

But then sometimes when seemingly no load is on the system i get
messages like:

somenumber excceeded spare time of someothernumber .... [can't reproduce
now, so don't know the exact text]

and the xrun callback of ardour and qjckctl  is called.. If you want i
can investigate the issue further if you let me know wht info could be
useful for you..

Am i right in suspecting that xruns can happen, too, when the jack
clients are too slow in delivering data which then causes jackd to be
too late delivering data to the alsa-driver? But this should ony happen
during large cpu loads caused by the jack clients? When some other
process generates the load and it is not SCHED_FIFO this should not
produce xruns because the jack and jack client processes get executed
first [SCHED_FIFO]. Or do i misunderstand the issues here?

Florian Schmidt

P.S.: just got one xrun [during the whole kernel build].. well, building
a kernel and stuff is maybe toooo much :)

-------------------------------------------------------
This SF.net email is sponsored by: SF.net Giveback Program.
Does SourceForge.net help you be more productive?  Does it
help you create better code?   SHARE THE LOVE, and help us help
YOU!  Click Here: http://sourceforge.net/donate/