Fri Sep 16 18:04:28 EDT 2011

jackd as user

Why does this keep breaking?  Every time I start using pd again I have
to spend half a day figuring out how to get sound and video to work..

I'd like to get pd back up an running for the Haskell DSP tests.  It
was working around october last year, but then I lost track of
configs.  Don't remember what happened.

First problem, starting jackd:

Cannot use real-time scheduling (RR/10)(1: Operation not permitted)

I don't remember.  Should I run pd setuid root, should I run pd and
jack as root, or was there some other permission thing to set?

chmod +s /usr/bin/pd
chmod +s /usr/bin/jackd

Looking a bit, I find this post[1] mentioning rlimits.  Let's remove
the setuid bits and try again.

However, [2] doesn't recommend rlimits, but mentions PAM instead.
My /etc/security/limits.conf already has this:

@audio          -       rtprio          100
@audio          -       nice            -10

I've added this line also:

@audio          -  memlock  unlimited

And yes, I'm member of the audio group.  Maybe I just need to login
again after recent upgrade?  Let's try.  Yep that was the problem.

[1] http://www.linuxquestions.org/questions/linux-kernel-70/realtime-scheduling-permission-for-user-783434/
[2] http://www.esaracco.fr/documentation/linuxaudio/linuxaudio/obtaining-realtime-privileges.html