Subject: Re: [RFC][PATCH] sched: avoid huge bonus to sleepers on busy
 machines
From: Mike Galbraith <efault@gmx.de>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Suresh Jayaraman <sjayaraman@suse.de>, Ingo Molnar <mingo@elte.hu>,
       linux-kernel@vger.kernel.org
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Date: Mon, 04 Jan 2010 13:49:18 +0100
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On Mon, 2010-01-04 at 13:36 +0100, Peter Zijlstra wrote:
> On Mon, 2010-01-04 at 13:30 +0100, Mike Galbraith wrote:
> > Any diddling of sleeper fairness would have to be accompanied with a
> > preemption model change methinks. 
> 
> Just told jays the exact same thing on IRC ;-)
> 
> Also, workloads are interesting, the signal test thing is the easiest to
> test the preemption side, various things like QPID show the down-side
> iirc.

Best testcase for the downside in my arsenal is vmark.  It performs a
_lot_ better with no wakeup preemption.  'Course if you run your box
that way, you quickly find out what a horrible idea that is :)

	-Mike

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