Re: [patch] SCHED_SOFTRR starve-free linux scheduling policy

Mike Galbraith (efault@gmx.de)
Mon, 14 Jul 2003 10:14:11 +0200


At 12:12 AM 7/14/2003 -0700, Davide Libenzi wrote:
>On Mon, 14 Jul 2003, Mike Galbraith wrote:
> > While testing, I spotted something pretty strange. It's not specific to
> > SCHED_SOFTRR, SCHED_RR causes it too. If I fire up xmms's gl visualization
> > with either policy, X stops getting enough sleep credit to stay at a usable
> > priority even when cpu usage is low. Fully repeatable weirdness. See
> > attached top snapshots.
>
>RT tasks are pretty powerfull and should not be used to run everything ;)
>What I was seeking with this patch was 1) deterministic latency 2) stave
>protection.

Yes, I know. I only fired up the cpu hog as a test to see that the
protection would kick in. I did do that too though, ran _everything_...
the whole X/KDE beast SCHED_SOFTRR for grins :)

I should have reported the strangeness in a different thread, it has
nothing to do with your patch.

-Mike

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