[PlanetCCRMA] jackd xruns problem: solved? (FC2 2.6.7rc4 O7 kernel)

[Janina Sajka]

Can you please remind me of the http address for the Planet Edge? I'd
like to try building the kernel from source for X86_64. Thanks.

Fernando Pablo Lopez-Lezcano writes:
> On Sat, 2004-08-14 at 12:48, Fernando Pablo Lopez-Lezcano wrote:
> > On Sat, 2004-08-14 at 08:26, Steve Harris wrote:
> > > On Fri, Aug 13, 2004 at 01:17:52 -0700, Fernando Pablo Lopez-Lezcano wrote:
> > > > > Then I tried to compile a 2.6.8-rc4 with CK2 and.. no more xruns!
> > > > > (with # jackd --realtime -Rv -d alsa -p 128 -n 3 -r 44100
> > > > >  and same applications running).
> > > > > 
> > > > > I must admit, I didn'to do hard testing by now, but
> > > > > I think it could be encouraging!
> > > > 
> > > > There has been a lot of progress in the last few weeks. I'm currently
> > > > running 2.6.8rc4 plus Ingo Molnar's volutary scheduling O5 and it is
> > > > looking very very good. The gurus are hard at work tracking hard stuff
> > > > that deals with mlockall...[*]
> > > 
> > > How serious are the mloclall problems? Any chance of throwing an RPM or
> > > kernel source over the fence?
> > 
> > Yes, I could do that. In fact I should have already done that.
> 
> Ok, Steve and other Fedora Core 2 bleeding edge users, I have the latest
> and greatest (as of yesterday, 2.6.8 final was released in between :-)
> over the fence. Has been tested to boot on all of two (2) machines, a P4
> latop and an Athlon64 desktop...
> 
> These are experimental packages. 
> You have been warned. 
> 
> I would only use these packages if you have been keeping up with the
> 2.6.x latency threads in the various mailing lists. 
> 
> I have just two _experimental_ packages - you have been warned, again -
> that are available:
>   kernel#2.6.7-0.1.rc4O7.ll.rhfc2.ccrma
>     2.6.7 rc4 + voluntary preemption O7
>   kernel-module-alsa-2.6.7-0.1.rc4O7.ll.rhfc2.ccrma
>     post 1.0.6 rc2 cvs snapshot with full xrun debugging enabled
> 
> To install you should add the planetedge repository (temporarily) to
> your /etc/apt/sources.list. Same as the "planetcore" line, just replace
> "planetcore" with "planetedge. 
> 
> To install the kernel (this is all manual installs):
>   apt-get install kernel#2.6.7-0.1.rc4O7.ll.rhfc2.ccrma
> To install the matching alsa driver:
>   apt-get install kernel-module-alsa-2.6.7-0.1.rc4O7.ll.rhfc2.ccrma
> (only uniprocessor i686 builds for now...)
> 
> Reboot and cross your fingers :-)
> 
> Tunables once you are up and running:
> 
> You should activate kernel preemption (not on by default):
>   echo "1"> /proc/sys/kernel/kernel_preemption
> Make sure voluntary preemption is on (at level 3):
>   cat /proc/sys/kernel/voluntary_preemption
> 
> Max sectors (or whatever) per transfer for the disks, optional:
>   cat /sys/block/hda/queue/max_sectors_kb
> (I set this to 16, did not really experiment a lot)
> 
> Enable reporting kernel traces for alsa xruns, optional:
>   echo "2"> /proc/asound/card0/pcm0p/xrun_debug
>   echo "2"> /proc/asound/card0/pcm0c/xrun_debug
> 
> Enable sysrq magic key combination to force sinc and reboot if machine
> hangs :-)
>   echo "1">/proc/sys/kernel/sysrq
> 
> Disable threaded interrupts for your soundcard(optional), use "cat
> /proc/interrupts" to find out which irq is used by your soundcard, then
> find it in /sys/irq/, see the "threaded variable under your soundcard,
> for my laptop this is what I use:
> 
>   echo "0"> /proc/irq/9/Intel\ 82801CA-ICH3/threaded
> 
> And finally... let me know what happens!!
> Enjoy!
> -- Fernando
> 
> 
> _______________________________________________
> PlanetCCRMA mailing list
> PlanetCCRMA@ccrma.stanford.edu
> http://ccrma-mail.stanford.edu/mailman/listinfo/planetccrma

-- 
	
				Janina Sajka, Chair
				Accessibility Workgroup
				Free Standards Group (FSG)

janina@freestandards.org	Phone: +1 202.494.7040