[PlanetCCRMA] jackd xruns problem: solved? (FC2 2.6.8.1+P9 kernel)

Rui Nuno Capela rncbc@rncbc.org
Wed Aug 25 03:13:01 2004


Hi Fernando et al.

>> In your opinion should I try this new kernel or wait?
>> I have a smb pentium III, but If this is unstable..
>
> Well, I don't know (if it is stable). I have not had a chance to test on
> a true multiprocessor machine yet (I'm not running fc2 on production
> machines so I have to grab one, get another disk and install fc2 to be
> able to test). Most probably tomorrow. Stay tuned :-)
>

Just to add some of my experience here, although not precisely Planet+FC2
related,.

I do have a HT enabled P4 currently test-running a SMP kernel patched with
voluntary_preempt-2.6.8.1-P9. It's a SUSE 9.1 box, but that's not the
point.

The thing to note is that I can't set voluntary_preemption>1 without
getting a complete system lockup in no time. Almost everytime it just
hangs on KDE 3.3 startup. Othertimes, is just suffices to start jackd -R
and the complete box is frozen. No kyeboard magic SysRq can even work to
the rescue :(

OTHO on my laptop I have a Mdk 10.0 with same kernel setup but UP. With
the default settings as kernel_preemption=1 and voluntary_preemption=3
everything seems to work without a glitch.

So I think that SMP/HT kernel 2.6.8.1 and voluntary_preempt>1 is far from
being stable. It's a showstopper.

Take care,
-- 
rncbc aka Rui Nuno Capela
rncbc@rncbc.org

P.S. My Planet box is pure SMP (2xP3) but still on FC1 with kernel 2.4.
It's a production box, so I refrain to test this stuff on it :)