Re: [PATCH] sleep_decay for interactivity 2.5.72 - testers needed

[Con Kolivas <kernel@kolivas.org>]

On Mon, 23 Jun 2003 01:40, Felipe Alfaro Solana wrote:
> On Sun, 2003-06-22 at 15:45, Con Kolivas wrote:
> > > Feel free to test it and comment. Things to look for - the dreaded
> > > audio skip under load, and X remaining interactive during sustained use
> > > under load.
>
> I must say this seems to be getting better, but I still prefer Mike's
> patches. With the latest sleep decay patch and 2.5.72-mm3, I can still
> easily starve XMMS audio for a long time (~5 seconds) on my 700Mhz
> Pentium III laptoñ (running RHL9 and KDE 3.1.2) simply by running "while
> true; do a=2; done" on a konsole window. Dragging a window fast enough
> also starves XMMS for ~5 seconds just until the scheduler adjusts the
> priorities.
>
> XMMS is running with an effective priority of 15 (that's what top says).
> "while true; do a=2; done" starts with a priority of 15 (which causes
> XMMS to stop playing sound), then it is detected as a CPU hog and every
> second its priority is increased by one. When its priority reaches 20,
> XMMS starts playing again.
>
> When I move windows around fast enough. the X server starts with a
> priority of 15, starving XMMS. If I keep moving windows around for a
> long time, X's priority starts increasing by one, until it reaches 20.
> At this moment, it stops disturbing XMMS audio playback.
>
> I've been playing with scheduler parameters, mainly by reducing
> MAX_SLEEP_AVG to (HZ) and STARVATION_LIMIT to (HZ). This seems to help a
> lot, although I can still make XMMS skip sound every once a bit.
> However, mplayer is a really hard one: I have been unable to make it
> skip sound yet.

Yes Mike's patches are definitely better. My patches are designed for the 
2.4-ck patchset which has other workarounds that augment this patch; however 
these workarounds are harder to stomach for mainstream kernels (read nasty 
hacks). I thought I'd offer the not so nasty sleep_decay patch in 2.5 form 
for perusal and comments since people are more willing to test 2.5 patches.

Con