Re: [PATCH V2 1/3] x86,idle: Quickly notice prediction failure forrepeat mode

From: Rik van Riel
Date: Mon Sep 17 2012 - 09:59:44 EST


On 09/17/2012 09:53 PM, Youquan Song wrote:
The prediction for future is difficult and when the cpuidle governor prediction
fails and govenor possibly choose the shallower C-state than it should. How to
quickly notice and find the failure becomes important for power saving.

cpuidle menu governor has a method to predict the repeat pattern if there are 8
C-states residency which are continuous and the same or very close, so it will
predict the next C-states residency will keep same residency time.

Could I convince you to try out my variation on
detect_repeating_intervals? :)

http://people.redhat.com/riel/cstate/cstate-stddev-converge.patch

I suspect that small change might help your code adapt to changed
conditions even faster.

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