Re: [GnomeMeeting-devel-list] Very bad sound with 2.6.0

[Christian Meder <chris onestepahead de>]

On Sat, 2003-12-20 at 17:13, Stefan Bruens wrote:
> Am Samstag, 20. Dezember 2003 16:49 schrieb Christian Meder:
> > On Sat, 2003-12-20 at 11:29, Johnny Strom wrote:
> > > Hello
> > >
> > >
> > > Is seems like the sound is so bad in Gnomemeeting plus OSS driver
> > > (es1371) in the 2.6.0 kernel that one can't hear what they say in the
> > > other end (Note it is the same in bouth directions).
> > >
> > > Have someone else tested this?
> >
> > Hi,
> >
> > I took the gnomemeeting regression from 2.4.2x to 2.6.0-testx (and up)
> > to the linux-kernel list yesterday. Search for the gnomemeeting thread
> > in
> >
> > http://www.ussg.iu.edu/hypermail/linux/kernel/0312.2/index.html
> >
> > I won't recap it all but I tried lots of different scenarios ALSA and
> > OSS, gnomemeeting and gnomemeeting-cvs, Con's scheduler and Nick's
> > scheduler, etc. (see thread) and I never got the same gnomemeeting
> > quality I get in 2.4.2x under any kind of CPU load other than
> > gnomemeeting.
> >
> > Probably it would help if Damien would review the thread and add any
> > missing gnomemeeting specific information which could be relevant to
> > this phenomenon. Specifically if there are any thread tricks
> > gnomemeeting is using because that's an area 2.6 is differing from 2.4.
> >
> >
> > 			Christian Meder
> 
> IIRC there was some problem with openoffice and sched_yield(), and as pwlib 
> uses sched_yield too ...
> 
> Sorry, I have no time nor enough experience with schedulers to look into this 
> myself.

Ok. You're right.

The code in pwlib

  if (errno == EINTR || errno == EAGAIN) {
    if (++retry < 1000) {
#if defined(P_RTEMS)
      sched_yield();
#else
      usleep(10000); // Basically just swap out thread to try and clear
blockage
#endif
      return TRUE;   // Return value to try again
    }
    // Give up and assert
  }

does look similar to the Openoffice problem "busy looping on
sched_yield() considered harmful". Although I've got no idea if it's
really the problem here. 



			Christian

-- 
Christian Meder, email: chris onestepahead de
 
What's the railroad to me ?
I never go to see
Where it ends.
It fills a few hollows,
And makes banks for the swallows, 
It sets the sand a-blowing,
And the blackberries a-growing.
                      (Henry David Thoreau)