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From: "Rafael J. Wysocki" <rafael@kernel.org>
Date: Thu, 4 Apr 2024 21:05:12 +0200
Message-ID: <CAJZ5v0iXZug9pcFbps8v0xpz6hwbcH8+_esOOTD=wgrmcfCDhA@mail.gmail.com>
Subject: Re: [PATCH] PM:EM: fix wrong utilization estimation in em_cpu_energy()
To: Lukasz Luba <lukasz.luba@arm.com>, Vincent Guittot <vincent.guittot@linaro.org>
Cc: rui.zhang@intel.com, amit.kucheria@verdurent.com, amit.kachhap@gmail.com, 
	daniel.lezcano@linaro.org, viresh.kumar@linaro.org, len.brown@intel.com, 
	pavel@ucw.cz, mhiramat@kernel.org, qyousef@layalina.io, wvw@google.com, 
	xuewen.yan94@gmail.com, rafael@kernel.org, linux-kernel@vger.kernel.org, 
	linux-pm@vger.kernel.org, dietmar.eggemann@arm.com
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On Thu, Apr 4, 2024 at 1:05=E2=80=AFPM Lukasz Luba <lukasz.luba@arm.com> wr=
ote:
>
> Hi Vincent,
>
> On 4/4/24 11:42, Vincent Guittot wrote:
> > Commit 1b600da51073 ("PM: EM: Optimize em_cpu_energy() and remove divis=
ion")
> > has added back map_util_perf() in em_cpu_energy() computation which has
> > been removed with the rework of scheduler/cpufreq interface.
> > This is wrong because sugov_effective_cpu_perf() already takes care of
> > mapping the utilization to a performance level.
> >
> > Fixes: 1b600da51073 ("PM: EM: Optimize em_cpu_energy() and remove divis=
ion")
> > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> > ---
> >   include/linux/energy_model.h | 1 -
> >   1 file changed, 1 deletion(-)
> >
> > diff --git a/include/linux/energy_model.h b/include/linux/energy_model.=
h
> > index 770755df852f..70cd7258cd29 100644
> > --- a/include/linux/energy_model.h
> > +++ b/include/linux/energy_model.h
> > @@ -245,7 +245,6 @@ static inline unsigned long em_cpu_energy(struct em=
_perf_domain *pd,
> >        * max utilization to the allowed CPU capacity before calculating
> >        * effective performance.
> >        */
> > -     max_util =3D map_util_perf(max_util);
> >       max_util =3D min(max_util, allowed_cpu_cap);
> >
> >       /*
>
> LGTM. It was developed in parallel IIRC and that change which removes
> the extra margin to the util was lost from my radar. I can see it
> landed first.
>
> Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>

Applied as 6.9-rc material, thanks!