Subject: Re: x264 benchmarks BFS vs CFS
From: Mike Galbraith <efault@gmx.de>
To: Ingo Molnar <mingo@elte.hu>
Cc: Jason Garrett-Glaser <darkshikari@gmail.com>,
       Kasper Sandberg <lkml@metanurb.dk>,
       Peter Zijlstra <a.p.zijlstra@chello.nl>,
       LKML Mailinglist <linux-kernel@vger.kernel.org>,
       Linus Torvalds <torvalds@linux-foundation.org>
In-Reply-To: <20091218052344.GD417@elte.hu>
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Date: Fri, 18 Dec 2009 08:30:05 +0100
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On Fri, 2009-12-18 at 06:23 +0100, Ingo Molnar wrote:

> Having said that, we generally try to make things perform well without apps 
> having to switch themselves to SCHED_BATCH. Mike, do you think we can make 
> x264 perform as well (or nearly as well) under SCHED_OTHER as under 
> SCHED_BATCH?

It's not bad as is, except for ultrafast mode.  START_DEBIT is the
biggest problem there.  I don't think SCHED_OTHER will ever match
SCHED_BATCH for this load, though I must say I haven't full-spectrum
tested.  This load really wants RR scheduling, and wakeup preemption
necessarily perturbs run order.

I'll probably piddle with it some more, it's an interesting load.

	-Mike

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