[LAU] Too many xruns

[Kevin Cosgrove]

On 11 October 2012 at 9:17, Kevin Cosgrove <kevinc at cosgroves.us> wrote:

> On 11 October 2012 at 6:55, Paul Davis <paul at linuxaudiosystems.com> wrote:
> 
> > 2.  chrt: failed to set pid 0's policy: Operation not permitted
> > >     Checking the ability to prioritize processes with chrt... no - not good
> > >     Could not assign a 80 rtprio value. Set up limits.conf.
> > >     For more information, see
> > >
> > > http://wiki.linuxmusicians.com/doku.php?id=system_configuration#limits.conf
> > >
> > >     I did make the changes outlined at the above link.  I still
> > >     get the above report.  I'm going to guess that I need some
> > >     real-time support from the kernel to make this work.  Which
> > >     brings me to
> > 
> > this is not true. http://jackaudio.org/realtime_vs_realtime_kernel
> 
> OK.  That's a pleasant answer.  :-)
> 
> I added this:
> 
> ::::::::::::::
> /etc/security/limits.d/93-audio_limits.conf
> ::::::::::::::
> # Increase priority of audio applications
> # maximum realtime priority
> @audio - rtprio 90
> # maximum locked-in-memory address space (KB)
> @audio - memlock 2000000
> 
> 
> Fedora's jack-audio-connection-kit-1.9.8-9.fc17.x86_64 package added this:
> 
> ::::::::::::::
> /etc/security/limits.d/95-jack.conf
> ::::::::::::::
> # Default limits for users of jack-audio-connection-kit
> 
> @jackuser - rtprio 70
> @jackuser - memlock 4194304
> 
> @pulse-rt - rtprio 20
> @pulse-rt - nice -20
> 
> > you *must* get these permissions correct ...
> 
> By permissions, are you meaning
> 
>   crw-rw---- 1 root audio  10, 228 Oct 10 22:47 /dev/hpet
>   crw-rw---- 1 root audio 254,   0 Oct 10 22:47 /dev/rtc0
> 
>   [kevinc #28] groups
>   kevinc root adm disk wheel cdrom man floppy games audio users jackuser

I enabled real-time jack in qjackctl a bit ago.  Then I ran
ardour in a play loop for about 40 minutes with ZERO xruns.
Yeah!  Last night playing ardour for 1 minute would have resulted
in several xruns.  I was doing this over the network, away from
the audio gear.  So, I couldn't tell what was happening in the
studio.  I also need to try recording still.  But, this is VERY
promising.  :-)

FWIW, running over the network with the slower screen update rate
allowed me to see the "RT" in the qjackctl window flash on/off.
I never knew it did that.  What does this mean?

Thanks...

--
Kevin