Re: [RFC PATCH v2 0/5] sched/cpufreq: Make schedutil energy aware

From: Peter Zijlstra
Date: Tue Jul 02 2019 - 11:44:33 EST


On Thu, Jun 27, 2019 at 06:15:58PM +0100, Douglas RAILLARD wrote:
> Make schedutil cpufreq governor energy-aware.
>
> - patch 1 introduces a function to retrieve a frequency given a base
> frequency and an energy cost margin.
> - patch 2 links Energy Model perf_domain to sugov_policy.
> - patch 3 updates get_next_freq() to make use of the Energy Model.

>
> 1) Selecting the highest possible frequency for a given cost. Some
> platforms can have lower frequencies that are less efficient than
> higher ones, in which case they should be skipped for most purposes.
> They can still be useful to give more freedom to thermal throttling
> mechanisms, but not under normal circumstances.
> note: the EM framework will warn about such OPPs "hertz/watts ratio
> non-monotonically decreasing"

Humm, for some reason I was thinking we explicitly skipped those OPPs
and they already weren't used.

This isn't in fact so, and these first few patches make it so?