[LAU] Xruns on Ubuntu 8.04, two machines

Rui Nuno Capela rncbc at rncbc.org
Tue Jun 17 14:06:08 EDT 2008

Johannes Mario Ringheim wrote:
> After upgrading to Ubuntu Hardy (8.04), I'm having (too many) xruns on 
> two different machines. Both worked perfectly on 7.04.
> On both machines the "RT" indicator on qjackctl keeps blinking. On 7.04 
> it was always dimmed, and everything worked fine. Does someone know what 
> that "RT" indicator in qjackctl means? When it is dimmed, do you not 
> have proper realtime scheduling?
> On my laptop, with a Behringer UCA202 USB soundcard, there are xruns on 
> some of the "RT" blinks. On my PC, with an M-Audio Delta66, there are 
> one xrun on the first blink, and on every subsequent blink a message 
> saying "XRUN callback (40 skipped).". Then there's about forty lines 
> saying "delay of 36196.000 usecs exceeds estimated spare time of 
> 11579.000; restart ...". I've included a portion of the jackd output below.

just a way of clarification.

the RT blinking is a recent "feature" of QjackCtl. you can turn it off 
in the Setup/Display/Blink server mode display option if you don't like 
it :)

the RT indication being there, either blinking or not, is a simple 
indication that the jack server is running in real-time mode. the 
blinking is just some lousy eye-candy, nothing more, nothing less ...

it just happens that qjackctl displays new xruns and blinks at the very 
same time (~2 second period). the xruns are happening in between (and 
count reported as "skipped") it just doesn't matter whether the RT 
indicator is blinking or not.

rncbc aka Rui Nuno Capela
rncbc at rncbc.org

More information about the Linux-audio-user mailing list