[LAU] Qjackctl 3.2, QT4, KDE 3.5.9, high CPU usage

[Rui Nuno Capela]

hanaghan at starband.net wrote:
> Hi folks...
> 
> I still running PCLinuxOS and using Thacś RPMś.
> 
> Without version numbers of lots of libs, the version numbers in the
> subject line are relevant to my system. Hopefully thatś enough.
> 
> 
> I set up a new box from the live CD and added all the audio stuff from
> apt. Everything worked fine...I updated to Qjackctl 3.2 from and older
> version even and still no problems. I then did a jumbo update out of
> Synaptic...
> 
> When I run Qjackctl or Qsynth in KDE, the CPU usage shoots to the moon.
> This has happened on another install of the same distro in the the very
> same sequence and manner. I dont think itś Qjackctl that is the
> issue..otherwise it would have done it when i first upgraded to 3.2 using
> QT4. Even though Qsynth shows the same symptoms, pointing toward a
> possible QT4 issue, that makes no sense either...again, it would have done
> it before.
> 
> I suspect something in KDE is doing it. I tried running from Fluxbox, and
> same thing...but doesn Fluxbox use some KDS libs anyway?
> 
> I guess I can install Gnome and try that but really dont want the clutter
> on the machine. Anyone know anything about this? I saw another post on
> Linuxquestions.org about the same thing on another distro...
> 
> TIA for any help.
> 

a very similar issue has been experienced before, iirc. it has been 
reported that on debian etch and ubuntu, qjackctl 0.3.x was peaking to 
100%cpu usage (not %dsp load) and right after jackd is started.

this issues blame has been pointed to libqt4 itself, more specifically 
to the QProcess class wich deals to process interface coordination and 
to the extent of my knowledge a mere qt4 upgrade, from the testing (or 
lenny) repositories, sufficed for the issue go away.

so it seems to be a strict qt4 issue, maybe related to the way it's 
built but not sure (i never had the issue duplicated myself)

hth

cheers
-- 
rncbc aka Rui Nuno Capela
rncbc at rncbc.org