Re: [PATCH v6 04/11] cpufreq/schedutil: use rt utilization tracking

From: Peter Zijlstra
Date: Fri Jun 22 2018 - 07:44:40 EST


On Fri, Jun 22, 2018 at 01:37:13PM +0200, Peter Zijlstra wrote:
> I suppose we can make it more complicated, something like:
>
> u u
> f := u + (--- - u) * (---)^n
> 1-r 1-r
>
> Where: u := cfs util
> r := \Sum !cfs util
> f := frequency request
>
> That would still satisfy all criteria I think:
>
> r = 0 -> f := u
> u = (1-r) -> f := 1
>
> and in particular:
>
> u << (1-r) -> f ~= u
>
> which casuses less inflation than the linear thing where there is idle
> time.

Note that for n=0 this last property is lost and we have the initial
linear case back.