syscons + mouse == stuttering playback

[Ulrich Spoerlein]

On Sat, 14.07.2007 at 21:09:26 +0200, Tijl Coosemans wrote:
> On Saturday 14 July 2007 20:44:10 Ulrich Spoerlein wrote:
> > On Sat, 14.07.2007 at 18:46:13 +0200, Tijl Coosemans wrote:
> > > On Monday 02 July 2007 20:51:09 Ulrich Spoerlein wrote:
> > > > on a recent CURRENT, without WITNESS or INVARIANTS. Both with
> > > > SCHED_ULE and SCHED_4BSD I observed the following:
> > > > 
> > > > Make sure almost nothing is running (to rule out other influences).
> > > > Run mpg123 on some MP3 file. Then start moving the syscons mouse
> > > > cursor. I get a high frequency stuttering on playback, playback is
> > > > also slowed down.
> > > 
> > > I just noticed it. I was playing music in Amarok, switched to a text
> > > terminal and moving the mouse there causes stuttering. In X it
> > > doesn't...
> > 
> > Are you using an USB mouse? I do, perhaps it is caused by the Giant
> > lock? I can't test with a PS/2 mouse, but perhaps I could run a test
> > with Hans' USB stack (giant free).
> 
> Yes, usb mouse, but this laptop touchpad (PS/2?) has the same effect.

Another interesting datapoint: playback over HPS' uaudio(4) is *not*
affected. Perhaps the problem is specific to Intel ICH audio?

FreeBSD Audio Driver (newpcm: 32bit 2007061600/i386)
Installed devices:
pcm0: <Intel ICH4 (82801DB)> at io 0xf4fff800, 0xf4fff400 irq 9 bufsz 16384 kld snd_ich [MPSAFE] (1p:2v/1r:1v channels duplex default)
pcm1: <USB audio> at ? kld snd_uaudio [GIANT] (1p:1v/1r:1v channels duplex)

Cheers,
Ulrich Spoerlein
-- 
"It is better to remain silent and be thought a fool,
than to speak, and remove all doubt."