linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Lukasz Luba <lukasz.luba@arm.com>
To: linux-kernel@vger.kernel.org
Cc: Chris.Redpath@arm.com, lukasz.luba@arm.com,
	dietmar.eggemann@arm.com, morten.rasmussen@arm.com,
	qperret@google.com, linux-pm@vger.kernel.org,
	peterz@infradead.org, rjw@rjwysocki.net, viresh.kumar@linaro.org,
	vincent.guittot@linaro.org, mingo@redhat.com,
	juri.lelli@redhat.com, rostedt@goodmis.org, segall@google.com,
	mgorman@suse.de, bristot@redhat.com, CCj.Yeh@mediatek.com
Subject: [PATCH 0/3] Improve EAS energy estimation and increase precision
Date: Fri, 25 Jun 2021 16:26:00 +0100	[thread overview]
Message-ID: <20210625152603.25960-1-lukasz.luba@arm.com> (raw)

Hi all,

The patch set aims to address a scenario for Energy Aware Scheduler,
where we estimate and compare energy values and miss a more precised results.
In some use cases estimations for two CPUs might give the same values
for a given task and it's utilization. Those values would be different
when we have a better precision and avoid this rounding error.
Thus, the decision of choosing a CPU for a waking-up task might also
be better.

We have received this feedback from our partners.

Address this rounding error issue and increase the precision of Energy Model
em_perf_state::cost values. This change should not affect other
subsystems in kernel: thermal IPA, PowerCap DTPM, etc, since they use
em_perf_state::power field, which is not touched. It also doesn't
trigger the need for updating all existing platforms to register EM and report
power values in different scale.

Regards,
Lukasz

Lukasz Luba (3):
  sched/fair: Prepare variables for increased precision of EAS estimated
    energy
  PM: EM: Make em_cpu_energy() able to return bigger values
  PM: EM: Increase energy calculation precision

 include/linux/energy_model.h | 11 +++++++----
 kernel/power/energy_model.c  |  3 ++-
 kernel/sched/fair.c          | 13 +++++++------
 3 files changed, 16 insertions(+), 11 deletions(-)

-- 
2.17.1


             reply	other threads:[~2021-06-25 15:26 UTC|newest]

Thread overview: 33+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-06-25 15:26 Lukasz Luba [this message]
2021-06-25 15:26 ` [PATCH 1/3] sched/fair: Prepare variables for increased precision of EAS estimated energy Lukasz Luba
2021-06-30 17:01   ` Rafael J. Wysocki
2021-06-30 17:28     ` Lukasz Luba
2021-07-02 19:07       ` Lukasz Luba
2021-07-07  7:07   ` Vincent Guittot
2021-07-07  7:49     ` Lukasz Luba
2021-07-07  8:00       ` Vincent Guittot
2021-07-07  8:23         ` Lukasz Luba
2021-07-07  9:37           ` Vincent Guittot
2021-07-07  9:48             ` Lukasz Luba
2021-07-07  9:56               ` Vincent Guittot
2021-07-07 10:06                 ` Lukasz Luba
2021-07-07 10:11                   ` Vincent Guittot
2021-07-07 10:29                     ` Lukasz Luba
2021-07-07 10:32                       ` Vincent Guittot
2021-07-07 10:41                         ` Lukasz Luba
2021-07-07 10:50                           ` Vincent Guittot
2021-07-07 11:02                             ` Lukasz Luba
2021-07-07 13:53                               ` Vincent Guittot
2021-07-07 14:25                                 ` Lukasz Luba
2021-07-07  9:45           ` Dietmar Eggemann
2021-07-07  9:54             ` Lukasz Luba
2021-06-25 15:26 ` [PATCH 2/3] PM: EM: Make em_cpu_energy() able to return bigger values Lukasz Luba
2021-07-05 12:44   ` Dietmar Eggemann
2021-07-06 19:44     ` Lukasz Luba
2021-07-07  7:07   ` Peter Zijlstra
2021-07-07  8:09     ` Lukasz Luba
2021-07-07 10:01       ` Peter Zijlstra
2021-07-07 10:23         ` Lukasz Luba
2021-06-25 15:26 ` [PATCH 3/3] PM: EM: Increase energy calculation precision Lukasz Luba
2021-07-05 12:45   ` Dietmar Eggemann
2021-07-06 19:51     ` Lukasz Luba

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210625152603.25960-1-lukasz.luba@arm.com \
    --to=lukasz.luba@arm.com \
    --cc=CCj.Yeh@mediatek.com \
    --cc=Chris.Redpath@arm.com \
    --cc=bristot@redhat.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=juri.lelli@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mgorman@suse.de \
    --cc=mingo@redhat.com \
    --cc=morten.rasmussen@arm.com \
    --cc=peterz@infradead.org \
    --cc=qperret@google.com \
    --cc=rjw@rjwysocki.net \
    --cc=rostedt@goodmis.org \
    --cc=segall@google.com \
    --cc=vincent.guittot@linaro.org \
    --cc=viresh.kumar@linaro.org \
    --subject='Re: [PATCH 0/3] Improve EAS energy estimation and increase precision' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).