[linux-audio-user] JACK configuration: Preventing system lockups

[Nathaniel Virgo]

Hi,

I'm playing a lot with SuperCollider, which means that I quite often 
overtax the processor within a JACK app.  When I was using a patched 2.4 
kernel it used to say it was "zombified" and need to be re-started, but 
since upgrading to Fedora Core 4 and the Planet CCRMA patched 2.6 kernel 
it just seems to lock up my system: I might still be able to hear some 
horribly distorted sound but the mouse pointer doesn't move and 
keypresses aren't registered for a very long time so I quite often have 
to do a hard reset (this sometimes used to happen with the 2.4 kernel 
when plugins in Ardour ran into denormal problems as well).  It also 
seems strange that  this can happen quite suddenly after several seconds 
of QJackCtl saying I'm only using a few percent of the CPU.

My question then, is is this a difference in the way JACK is 
configured?  Can I set it up so that it will zombify processes before 
they lock up the GUI?  I tried running Jack in soft mode but I could 
hardly do anything without getting loads of dropouts. 

On a related note, is there a JACK configuration HOWTO anywhere?  Things 
I am currently mystified by include the meaning of the phrase "periods 
per buffer" and how to tell whether my (cheapo laptop internal) 
soundcard should work better at 44100Hz or 48000.

Thanks in advance for any help,

Nathaniel Virgo