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2003 Feb 26 17:08

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Re: [vox-tech] Skipping sound
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Re: [vox-tech] Skipping sound



On Wed, Feb 26, 2003 at 01:55:06PM -0800, Peter Jay Salzman wrote:
> begin Samuel Merritt <spam@andcheese.org> 
> > Running twm, mpg123 in an xterm, and Mozilla with X niced to 0, the
> > sound still skips when I scroll in Mozilla.
> > 
> > The skipping even happens with "play" (wave file player), and this
> > machine is grossly overpowered for just playing music and running X, so
> > I doubt it's a CPU time issue. 
>  
> kay.  wasn't sure what kind of machine it was.
> 
> > I'm actually running Mandrake 9.0 on the machine in question, and X
> > started out niced to -10. 
>  
> stupid question.  you looked at top while moving a window around?
> did you see anything interesting?

If I move the mouse pretty fast while dragging a window around in opaque
mode, I can get X to take up 60% CPU or so. I've never seen a media
player take more than 2-3% CPU on this machine. 
 
> also, is this a new symptom?  or has it always been happening and you
> just now sent an email out about it?

It's new; my (AGP) good video card's fan died, frying the chip, so while
I wait for a replacement, I'm using an old (PCI) Mystique. It wasn't a
problem with the now-defunct video card. 

> > Also, I forgot to mention earlier that I've ruled out an IRQ conflict.
> > Theoretically, since they're both PCI devices, the sound and video cards
> > should be able to share an IRQ, but I moved the video card around to
> > ensure that they're on different IRQs. 
> 
> i don't think every video card uses irq.   some video cards get polled
> by the CPU and fetch data by explicit read accesses to I/O memory.
> voodoo 4/5, 1/2 and mach cards are like this.  don't know about matrox.
> but you should be able to tell using lspci -vb.

The relevant output is: 

02:05.0 VGA compatible controller: Matrox Graphics, Inc. MGA 1064SG
[Mystique] (
rev 03) (prog-if 00 [VGA])
        Subsystem: Matrox Graphics, Inc.: Unknown device 1000
        Flags: bus master, stepping, medium devsel, latency 32, IRQ 15
        Memory at fa800000 (32-bit, prefetchable)
        Memory at f8000000 (32-bit, non-prefetchable)
        Memory at f7800000 (32-bit, non-prefetchable)

I don't know what it means, though. 

> odd.  i guess i'm most curious about the "is this something new or has
> always been a problem" question.
> 
> pete
> 
> 
> > On Wed, Feb 26, 2003 at 12:38:13PM -0800, Peter Jay Salzman wrote:
> > > sam,
> > > 
> > > have you tried with a different window manager?   do you get the
> > > skipping around when you use mp3blaster/mpg123 under twm?   that might be a
> > > good litmus test.
> > > 
> > > also, you run debian, right?  see if the "X" process is un-niced.
> > > debian now asks you if you want to run X with a higher priority.
> > > 
> > > try to renice X to 0.  see if that helps the skipping around.
> > > 
> > > pete
> > > 
> > > 
> > > begin Samuel Merritt <spam@andcheese.org> 
> > > > If I have music playing and I move a window around, switch windows, or
> > > > scroll a window, the music stutters. I'm using XFree86 4.2.1 and ALSA
> > > > 0.9.0rc2 (defaults for Mandrake 9). 
> > > > 
> > > > This happens in any video mode I try, from 1024x768, 24bpp down to
> > > > 640x480, 8bpp, though the stuttering is worse in higher resolutions and
> > > > color depths.
> > > > 
> > > > I've also tried switching between ALSA and OSS. It makes no difference. 
> > > > 
> > > > The video card is a Matrox Mystique with 4MB video RAM (MGA 1064SG). 
> > > > The sound card is an onboard CM8738. 
> > > > 
> > > > I'd heard about problems like this years ago, having to do with the
> > > > video card drivers hogging the PCI bus for long periods of time. I
> > > > played with the option "PciRetry", found in the mga(4) man page. The
> > > > stuttering is the same whether this option is on or off. 
> > > > 
> > > > Google doesn't come up with any relevant results; I did find a whole
> > > > bunch of pages about a setting that goes in system.ini, but I don't have
> > > > one of those. =)
> > > > 
> > > > 
> > > > -- 
> > > > Samuel Merritt
> > > > OpenPGP key is at http://meat.andcheese.org/~spam/spam_at_andcheese_dot_org.asc
> > > > Information about PGP can be found at http://www.mindspring.com/~aegreene/pgp/
> > > 
> > > 
> > > 
> > > -- 
> > > First they ignore you, then they laugh at you, then they fight you,
> > > then you win. -- Gandhi, being prophetic about Linux.
> > > 
> > > Fingerprint: B9F1 6CF3 47C4 7CD8 D33E 70A9 A3B9 1945 67EA 951D
> > > _______________________________________________
> > > vox-tech mailing list
> > > vox-tech@lists.lugod.org
> > > http://lists.lugod.org/mailman/listinfo/vox-tech
> > 
> > -- 
> > Samuel Merritt
> > OpenPGP key is at http://meat.andcheese.org/~spam/spam_at_andcheese_dot_org.asc
> > Information about PGP can be found at http://www.mindspring.com/~aegreene/pgp/
> 
> 
> 
> -- 
> First they ignore you, then they laugh at you, then they fight you,
> then you win. -- Gandhi, being prophetic about Linux.
> 
> Fingerprint: B9F1 6CF3 47C4 7CD8 D33E 70A9 A3B9 1945 67EA 951D
> _______________________________________________
> vox-tech mailing list
> vox-tech@lists.lugod.org
> http://lists.lugod.org/mailman/listinfo/vox-tech

-- 
Samuel Merritt
OpenPGP key is at http://meat.andcheese.org/~spam/spam_at_andcheese_dot_org.asc
Information about PGP can be found at http://www.mindspring.com/~aegreene/pgp/

Attachment: pgp00016.pgp
Description: PGP signature



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