Re: 2.6.8-rc2-mm2, staircase sched and ESD

From: Martin Schlemmer
Date: Tue Aug 10 2004 - 17:08:17 EST


On Thu, 2004-08-05 at 00:31, Con Kolivas wrote:
> Zan Lynx writes:
>
> > The 2.6.8-rc2-mm2 kernel has the staircase scheduler, right? Well, I am
> > seeing an odd thing. At least, I think it is odd.
> >
> > I'm running Fedora Core 2 and playing music with Rhythmbox. When I
> > watch top sorted by priority, I see esd slowly increase its priority
> > until it reaches 38, then it goes back to 20. ESD is only using 1-2%
> > CPU.
> >
> > This is causing a problem because doing just about anything in X, like
> > bring up a new window or drag a window causes the sound to just stop.
> >
> > Why does ESD's priority keep climbing?
> >
> > Oh yes, this does not happen if I change /proc/sys/fs/interactive to 0.
> > When it is 0, X's priority climbs faster than ESDs and does not cause
> > the problem.
>
> Yes this is a known issue with esd. It basically wakes up far too frequently
> for it's own good. esd should not be required with alsa drivers and
> 2.6 since alsa supports sharing of the sound card / mixing on it's own so
> adding esd adds an unnecessary layer to the sound drivers. It ends
> up doing this:
> esd->oss emulation->alsa.
>

This is not entirely true - or at least not on a more modern
distro that uses alsa:

---
nosferatu root # lsof | grep esd | grep /dev
esd 8886 azarah mem CHR 116,16 6226 /dev/snd/pcmC0D0p
esd 8886 azarah 0r CHR 1,3 756 /dev/null
esd 8886 azarah 1u CHR 4,4 1193 /dev/vc/4
esd 8886 azarah 2u CHR 4,4 1193 /dev/vc/4
esd 8886 azarah 29u CHR 116,16 6226 /dev/snd/pcmC0D0p
esd 8886 azarah 30r CHR 116,33 6058 /dev/snd/timer
esd 16748 azarah mem CHR 116,16 6226 /dev/snd/pcmC0D0p
esd 16748 azarah 29u CHR 116,16 6226 /dev/snd/pcmC0D0p
nosferatu root # ldd `which esd` | grep asound
libasound.so.2 => /usr/lib/libasound.so.2 (0x41b0d000)
nosferatu root #
---

--
Martin Schlemmer

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