Re: [PATCH RFC 5/7] sched: cfs: cpu frequency scaling arch functions

From: Rik van Riel
Date: Wed Oct 22 2014 - 16:07:54 EST


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On 10/22/2014 02:07 AM, Mike Turquette wrote:
> arch_eval_cpu_freq and arch_scale_cpu_freq are added to allow the
> scheduler to evaluate if cpu frequency should change and to invoke
> that change from a safe context.
>
> They are weakly defined arch functions that do nothing by default.
> A CPUfreq governor could use these functions to implement a
> frequency scaling policy based on updates to per-task statistics or
> updates to per-cpu utilization.
>
> As discussed at Linux Plumbers Conference 2014, the goal will be
> to focus on a single cpu frequency scaling policy that works for
> everyone. That may mean that the weak arch functions definitions
> can be removed entirely and a single policy implements that logic
> for all architectures.

On virtual machines, we probably want to use both frequency and
steal time to calculate the factor.

- --
All rights reversed
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