[linux-audio-dev] Linux 2.6 not a latency panacea?

[Takashi Iwai]

At Thu, 14 Aug 2003 02:48:40 +0200,
Christian Henz wrote:
> 
> On Wed, Aug 13, 2003 at 03:09:10PM -0700, Joshua Haberman wrote:
> > I am distressed.  It was my understanding that the 2.5/2.6 kernel branch 
> > was undergoing significant scheduler and latency work, and that 2.6 
> > would eliminate the kernel from the list of obstacles of low-latency on 
> > Linux.  It will have the preemptable kernel patch, the new scheduler, 
> > and all of Ingo Molnar's low-latency work.  Claims were being thrown 
> > around that 2.6 would be the lowest-latency operating system on the planet.
> > 
> > So how is it that we're in the 2.6.0-test series and people are 
> > complaining about audio skipping in **XMMS**, which uses three second 
> > buffers by default??  If people are getting skips from high-latency 
> > playback, what hope is there for low-latency audio?  A series of patches 
> > are coming from both Ingo and Con Kolivas attempting to address this, 
> > but the fact they are just now throwing around potential solutions 
> > erodes at my faith that they really understand the problem or how to 
> > solve it.
> > 
> > Is 2.6.x going to be suitable for low-latency (or even reliable 
> > high-latency) audio?  Or is it going to be more of the same: patching 
> > the kernel, tweaking parameters, reading magical incantations, and 
> > hoping for the best?
> > 
> > Reassure me please!
> > 
> > Josh
> > 
> 
> I also found 2.6.0-test[123] to be less responsive than 2.4.x-ll, or even stock 2.4.x. I've also experienced XMMS dropouts under load (for example compiling Muse)
> 
> Some behaviour I've noticed is that under heavy load the desktop/audio doesn't freeze for a certain block of time, but rather in short (~2 seconds) intervalls...

this should have been imporved significantly in -mm tree.
even reducing the min/max timeslices would help a lot.  the default
values look too large for desktop users...


Takashi