[LAU] JACK and realtime in Ubuntu 7.10

Peter Clarke pgclarke at beeb.net
Sun Dec 2 03:43:31 EST 2007


I'm having problems with realtime in JACK in my newly installed Ubuntu 7.10.

If I start qjackctl as a normal user - even the user with "admin" privileges - 
I cannot start the jack server in realtime mode.  The error is:

cannot use real-time scheduling (FIFO at priority 10) [for thread -1210406208, 
from thread -1210406208] (1: Operation not permitted)

But if I start qjackctl with sudo, realtime works fine.

I remember from my previous Gentoo system that I had to install modules 
realtime and realtime-lsm, and the user had to be a member of group realtime.  
But none of that seems to apply to Ubuntu, because it uses a specially 
patched kernel; am I correct about that?

Output of uname -a is:
Linux peter-desktop 2.6.22-14-rt #1 SMP PREEMPT RT Mon Oct 15 01:05:51 GMT 
2007 i686 GNU/Linux

The jackd command generated by qjackctl is:
/usr/bin/jackd -R -dalsa -r44100 -p1024 -n4 -D -Chw:0,0 -Phw:0,0 -s -S -i2 -o2

So my question is:  how can I run jack as a normal user in Ubuntu?

Peter C



More information about the Linux-audio-user mailing list