[linux-audio-user] RT and Jack problems

[Lee Revell]

On Wed, 2006-06-21 at 22:30 +0200, Hiram Abiff wrote:
> Quoting Mark Knecht <markknecht at gmail.com>:
> 
> > Hiram,
> >   There are a few things to discover:
> >
> > 1) Are you running Jack as root or a user?
> >
> > - First, try running Jack as root and see if these problems go away.
> >
> Gruß Dich, Mark
> I tried running it as root, works great.
> 
> > 2) Assuming you run as root without problems then the issue here is
> > probably one of permissions. However it is not /dev/rtc that needs to
> > be changed. Infact, nothing in /dev should be changed for this to
> > work. You either need to install the realtime-lsm package, create a
> > realtime group, add yourself to that group, and then load the realtime
> > module telling it to grant realtime permissions to that group. For
> > this to work you need a kernel with Linux Capabilities enabled in the
> > security section of the .config file.
> 
> I recompiled my kernel with the required module, I created a realtime
> group, added my user to it and loaded the module. lsmod reports
> it's loaded. However, I still get the same error messages when running
> muse. :(
> 
> I also noticed that when running qsampler with ALSA output, not JACK,
> I get this in the messages window:
> 
> 22:30:07.751 Channel 0 Some channel settings could not be set. Sorry.
> Thread: WARNING, can't assign realtime scheduling to thread!: Operation 
> not permitted
> Thread: WARNING, can't mlockall() memory!: Cannot allocate memory
> 

How did you load the realtime module?  You have to do "modprobe realtime
gid=$FOO" where $FOO is the number of your realtime group.

Also, you must log out and log back in for changes in group membership
to take effect.

Lee

> >
> > Alternatively there is a PAM based solution to this that is newer but
> > I haven't used it.
> >
> > Hope this helps,
> > Mark
> >
> 
> It does.
> 
> Hiram.
>