[linux-audio-dev] NPTL/2.6 (was snd-hdsp oddities)

[Fernando Pablo Lopez-Lezcano]

On Mon, 2004-07-05 at 09:24, Michael Ost wrote:
> On Thu, 2004-07-01 at 19:16, Paul Davis wrote:
> > When the dust settles from the kernel and NPTL, 2.6 will be more
> > viable. Right now, even though it works for some people, its not a
> > generally viable platform for realtime audio.
> 
> What sort of issues are you seeing with NPTL and the 2.6 kernel? Are
> there stability problems? Functionality problems? I thought I had heard
> the NPTL/2.6 was working fine.

What I'm seeing is, sometimes, xrun storms (this is using 2.6.7 + some
extra patches, lsm for realtime as non-root, recent alsa, qjackctl for
starting and running jack). One of them I think I have tracked to an app
running into denormal problems on a PIV. I still don't know for sure
which part of the system is contributing to the problem (jack / nptl /
alsa). On the same hardware with an older glibc and 2.4.x with low
latency patches I don't see the same problems (but the whole distro is
different, FC1 vs FC2). 

Some users have had good experiences with 2.6.x by turning off nptl with
the LD_ASSUME_KERNEL trick, but they get lousy performance (ie: lots of
xruns) with nptl on. 

-- Fernando