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Subject: Re: [PATCH 14/16] sched: make __update_entity_runnable_avg() fast
From: Peter Zijlstra <a.p.zijlstra@chello.nl>
To: Paul Turner <pjt@google.com>
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Date: Wed, 04 Jul 2012 18:51:54 +0200
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On Wed, 2012-06-27 at 19:24 -0700, Paul Turner wrote:
> +#define LOAD_AVG_MAX_N 516 /* number of full periods it takes to produce max */

y=sqrt(sqrt(sqrt(sqrt(sqrt(0.5)))))
l(1/1024)/l(y)
319.99999999999999998938
1024*y^320
.99999999999999998976

So after only 320 periods the contribution of the term is too small to
matter.