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Subject: Re: ppc32: Weird process scheduling behaviour with 2.6.24-rc
From: Michel =?ISO-8859-1?Q?D=E4nzer?= <michel@tungstengraphics.com>
To: Ingo Molnar <mingo@elte.hu>
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Date: Tue, 29 Jan 2008 11:14:29 +0100
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Cc: linuxppc-dev@ozlabs.org, Peter Zijlstra <a.p.zijlstra@chello.nl>,
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On Mon, 2008-01-28 at 13:56 +0100, Ingo Molnar wrote: 
> * Peter Zijlstra <a.p.zijlstra@chello.nl> wrote:
> 
> > > i think it would be OK to do half of this: make it easier to preempt 
> > > a +nice task. Michel, do you really need the -nice portion as well? 
> > > It's not a problem to super-preempt positively reniced tasks, but it 
> > > can be quite annoying if negatively reniced tasks have super-slices.
> > 
> > This should do that (unless I need a stronger cup of tea).
> 
> cool - thanks Peter. Michel, could you check Peter's patch, does it 
> resolve all the interactivity problems you've been seeing?

I'm now running with this patch and Srivatsa's patch, and together they
provide good interactivity even with CONFIG_FAIR_USER_SCHED enabled and
the default value of /proc/sys/kernel/sched_wakeup_granularity_ns. :) So
both patches seem to have the expected effect.

/proc/sys/kernel/sched_features contains 7.


Thanks,


-- 
Earthling Michel Dänzer           |          http://tungstengraphics.com
Libre software enthusiast         |          Debian, X and DRI developer