[LAU] jackd in realtime as user: a no-go in spite of modifying limits.conf

Dave Phillips dlphillips at woh.rr.com
Fri Nov 20 07:28:01 EST 2009

Der Mickster wrote:
> Hey,
> Can't seem to start jackd in realtime as user on ubuntu studio. It
> does start as root, but that's hardly a consolation (unless I run all
> audio software as root, which would be kinda daft IMO)
> @audio - rtprio 99
> @audio - nice -10
> @audio - memlock unlimited
> have been added to /etc/security/limits.conf
> Nevertheless, starting it as user just doesn't seem to work, and I
> just can't figure out why. I've googled the issue, and everybody seems
> to agree that modifying limits.conf in the above manner should solve
> the problem - yet this is what I get:
> mick at kaizoku:~$ jackd -R -P89 -dalsa -dhw:0 -r48000 -p256 -n3 -S &
> [1] 3092
> mick at kaizoku:~$ no message buffer overruns
> jackd 0.116.1
> Copyright 2001-2005 Paul Davis and others.
> jackd comes with ABSOLUTELY NO WARRANTY
> This is free software, and you are welcome to redistribute it
> under certain conditions; see the file COPYING for details
> JACK compiled with System V SHM support.
> cannot use real-time scheduling (FIFO at priority 10) [for thread
> -1217255744, from thread -1217255744] (1: Operation not permitted)
> cannot create engine
> Any ideas?

If you haven't already disabled PulseAudio do so at once. :) See this 
article for the howto:


The method might also work for 9.10, but so far I haven't needed it. I'm 
running a 2.6.31 non-rt kernel that's playing nicely with JACK, though I 
haven't yet tested it with any stress. The installer automatically added 
the 2.6.31-rt kernel to grub, I'll test it asap.

Sorry to blow my own horn here (again), but you might also look at this 
article to see if it has any ideas for you:




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