[Alsa-devel] Re: [linux-audio-dev] snd-hdsp oddities

[Takashi Iwai]

At Fri, 2 Jul 2004 13:26:44 +0200,
Florian Schmidt wrote:
> 
> On Fri, 02 Jul 2004 11:40:28 +0200
> Takashi Iwai <tiwai at suse.de> 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.
> > 
> > Hmm, except for some sched policy setting problems on NPTL, I don't
> > see bigger problem than 2.4+preempt kernel.  For some people,
> > 2.4+preempt might work _casually_ better than 2.6, but it can happen
> > vice versa.
> > 
> > Shouting "DON'T USE 2.6" isn't a good solution.  Though, we need to
> > inform to "set LD_ASSUME_KERNEL as a workaround"...
> 
> Yes, but i wonder: many other people use NPTL for many kinds of
> applications w/o problems.. The jack source code is too complex for me
> to really find my way through it, but maybe someone might consider
> summing up how jack handles threads and provide pointers into the
> source at the relevant spots.. Maybe NPTL isn't at fault, but jack.. 

Well, it's hard to determine at this point.
It could be a bug of pthread_setschedparm() on NPTL.

> Also, i think it would be very useful to have  simplified test case
> which shows the "erraneous" behaviour of jack/NPTL..  

Yes, definitely.


Takashi