Messages in this thread | | | Date | Thu, 3 Mar 2016 16:38:17 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH 6/6] cpufreq: schedutil: New governor based on scheduler utilization data |
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On Thu, Mar 03, 2016 at 03:01:15PM +0100, Vincent Guittot wrote: > > In case a more formal derivation of this formula is needed, it is > > based on the following 3 assumptions: > > > > (1) Performance is a linear function of frequency. > > (2) Required performance is a linear function of the utilization ratio > > x = util/max as provided by the scheduler (0 <= x <= 1). > > Just to mention that the utilization that you are using, varies with > the frequency which add another variable in your equation
Right, x86 hasn't implemented arch_scale_freq_capacity(), so the utilization values we use are all over the map. If we lower freq, the util will go up, which would result in us bumping the freq again, etc..
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