Re: [RFC][PATCH] Multimedia scheduling class, take 2

[Peter Zijlstra <peterz@infradead.org>]

On Tue, 2009-05-12 at 13:07 +0300, Jussi Laako wrote:
> Peter Zijlstra wrote:
> > I certainly don't think the current situation is bad enough to warrant
> > things like that, media on my machines works peachy (*cheer* for XV on
> > R600).
> 
> By the way, here's a good test case for a desktop, preferably UP:
>  - run something like this in a loop:
> 	find / -type f -exec grep asd "{}" ";"
>  - run x11perf * numcpus in a loop
>  - run glxgears * numcpus
>  - go to youtube frontpage with a web browser
>  - start for example "totem" mediaplayer and play full-HD H.264 movie
> 
> Does the movie playback and audio go smoothly? Can you play youtube HD
> videos smoothly?

I don't know about youtube, that flash thing doesn't seem to deliver
full hd content, and I'm not sure where to click, but playing a full-hd
trailer from the network using vlc seems to work just fine with 4
x11perf and 4 glxgears and that find thing.

There is an occasional stutter, but not much.

Thing is, adding static preemption priories into SCHED_OTHER (which is
basically what you propose I think) doesn't really help, I can still
load the machine high enough so that there simply isn't time available
to decode the frames while maintaining proportional fairness -- no
matter how preemptive you get.