Date: Mon, 14 May 2007 12:31:20 +0200
From: Ingo Molnar <mingo@elte.hu>
To: William Lee Irwin III <wli@holomorphy.com>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>, efault@gmx.de, tingy@cs.umass.edu,
       linux-kernel@vger.kernel.org
Subject: Re: fair clock use in CFS
Message-ID: <20070514103120.GA23766@elte.hu>
References: <20070514083358.GA29775@in.ibm.com> <20070514102929.GL31925@holomorphy.com>
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* William Lee Irwin III <wli@holomorphy.com> wrote:

> On Mon, May 14, 2007 at 02:03:58PM +0530, Srivatsa Vaddagiri wrote:
> > 	I have been brooding over how fair clock is computed/used in
> > CFS and thought I would ask the experts to avoid wrong guesses!
> > As I understand, fair_clock is a monotonously increasing clock which
> > advances at a pace inversely proportional to the load on the runqueue.
> > If load = 1 (task), it will advance at same pace as wall clock, as 
> > load increases it advances slower than wall clock.
> > In addition, following calculations depend on fair clock: task's wait
> > time on runqueue and sleep time outside the runqueue (both reflected in
> > p->wait_run_time).
> 
> It's not hard to see that that's a mistake. [...]

please clarify - exactly what is a mistake? Thanks,

	Ingo
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