[LAU] Realtime, but many xruns when jack is started. Debian Etch

Nigel Henry cave.dnb at tiscali.fr
Sun Sep 30 10:02:47 EDT 2007


On Debian Etch, using kernel 2.6.18-5-686, which I presume is a realtime one, 
as when I start jack with qjackctl, and with the realtime box checked, jack 
doesn't complain.

Looking at messages though, shows lots of xruns, although no music apps are 
being used.

I had this problem on Fedora 7. I'd installed the low latency kernel, and 
associated packages from planetccrma, and again jacks messages were showing 
lots of xruns. There was an updated pam that came with the kernel download, 
which left an /etc/security/limits.conf.rpmnew, and Fernando suggested adding 
the changes to the existing file, as the default setup for 
jack-audio-connection-kit in the limits.conf file set rtprio at 20.

That resolved the problem on Fedora 7. No more messages about xruns.

I tried the same few lines, as below, in the limits.conf file in Etch, but to 
no success, and there are no default priorities for jack there anyway.


# limit realtime and memory locking access to users in the group audio
# there is no way to say "allow locking all memory", 4G should be enough
#
#*  - rtprio  0
#*  - nice  0
#
#@audio  - rtprio  99
#@audio  - nice  -10
#@audio  - memlock  4000000

# or (default) allow everyone access
*  - rtprio  99
*  - nice  -10
*  - memlock  4000000


I don't have the realtime-lsm package installed on Etch yet, as I wanted to 
get opinions from the list first.

Thanks for any help/suggestions.

Nigel.

jackd is version 0.101.1-2    on Etch
qjackctl is version 0.2.21-1



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