All of lore.kernel.org
 help / color / mirror / Atom feed
From: Douglas Raillard <douglas.raillard@arm.com>
To: Peter Zijlstra <peterz@infradead.org>,
	Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: Quentin Perret <qperret@google.com>,
	linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
	mingo@redhat.com, rjw@rjwysocki.net, viresh.kumar@linaro.org,
	juri.lelli@redhat.com, vincent.guittot@linaro.org,
	Quentin Perret <qperret@google.com>,
	patrick.bellasi@matbug.net, dh.han@samsung.com
Subject: Re: [RFC PATCH v3 0/6] sched/cpufreq: Make schedutil energy aware
Date: Fri, 18 Oct 2019 18:24:57 +0100	[thread overview]
Message-ID: <65894424-3fdc-2b82-c84d-dac61aded5ea@arm.com> (raw)
In-Reply-To: <20191018075957.GD2328@hirez.programming.kicks-ass.net>



On 10/18/19 8:59 AM, Peter Zijlstra wrote:
> On Fri, Oct 18, 2019 at 09:44:44AM +0200, Dietmar Eggemann wrote:
>> On 17/10/2019 16:11, Peter Zijlstra wrote:
>>> On Thu, Oct 17, 2019 at 12:11:16PM +0100, Quentin Perret wrote:
>>
>> [...]
>>
>>> It only boosts when 'rq->cfs.avg.util' increases while
>>> 'rq->cfs.avg.util_est.enqueued' remains unchanged (and util > util_est
>>> obv).
>>>
>>> This condition can be true for select_task_rq_fair(), because that is
>>> ran before we do enqueue_task_fair() (for obvious raisins).
>>>
>>>>> I'm still thinking about the exact means you're using to raise C; that
>>>>> is, the 'util - util_est' as cost_margin. It hurts my brain still.
>>>>
>>>> +1 ...
>>>
>>> cost_i = capacity_i / power_i ; for the i-th OPP
>>
>> I get confused by this definition. efficiency=capacity/power but the
>> cs->cost value used in em_pd_get_higher_freq() is defined as
>>
>> cs_cost = cs->power * cpu_max_freq / cs->freq [energy_model.h]
> 
> Well, chalk that up to confusion inspired by the Changelog of patch 1.

I've updated the commit message to include that ordering OPPs by
increasing efficiency=capa/power on one CPU leads to the same ordering
as ordering by decreasing cost=power*f_max/f.

efficiency=(cpu_max_capa/1024) * (f/f_max) / power
efficiency=(cpu_max_capa/1024) / cost


> Let me redo it with that formula then.
> 

  reply	other threads:[~2019-10-18 17:25 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-11 13:44 [RFC PATCH v3 0/6] sched/cpufreq: Make schedutil energy aware Douglas RAILLARD
2019-10-11 13:44 ` [RFC PATCH v3 1/6] PM: Introduce em_pd_get_higher_freq() Douglas RAILLARD
2019-10-17  8:57   ` Dietmar Eggemann
2019-10-17  9:58   ` Dietmar Eggemann
2019-10-17 11:09     ` Douglas Raillard
2019-10-11 13:44 ` [RFC PATCH v3 2/6] sched/cpufreq: Attach perf domain to sugov policy Douglas RAILLARD
2019-10-17  8:57   ` Dietmar Eggemann
2019-10-17 10:22     ` Douglas Raillard
2019-10-11 13:44 ` [RFC PATCH v3 3/6] sched/cpufreq: Hook em_pd_get_higher_power() into get_next_freq() Douglas RAILLARD
2019-10-11 13:44 ` [RFC PATCH v3 4/6] sched/cpufreq: Introduce sugov_cpu_ramp_boost Douglas RAILLARD
2019-10-14 14:33   ` Peter Zijlstra
2019-10-14 15:32     ` Douglas Raillard
2019-10-17  8:57   ` Dietmar Eggemann
2019-10-17 11:19     ` Douglas Raillard
2019-10-11 13:44 ` [RFC PATCH v3 5/6] sched/cpufreq: Boost schedutil frequency ramp up Douglas RAILLARD
2019-10-17  9:21   ` Dietmar Eggemann
2019-10-11 13:45 ` [RFC PATCH v3 6/6] sched/cpufreq: Add schedutil_em_tp tracepoint Douglas RAILLARD
2019-10-14 14:53 ` [RFC PATCH v3 0/6] sched/cpufreq: Make schedutil energy aware Peter Zijlstra
2019-10-14 15:50   ` Douglas Raillard
2019-10-17  9:50     ` Peter Zijlstra
2019-10-17 11:11       ` Quentin Perret
2019-10-17 14:11         ` Peter Zijlstra
2019-10-18  7:44           ` Dietmar Eggemann
2019-10-18  7:59             ` Peter Zijlstra
2019-10-18 17:24               ` Douglas Raillard [this message]
2019-10-18  8:11             ` Peter Zijlstra
2019-10-17 14:23       ` Douglas Raillard
2019-10-17 14:53         ` Peter Zijlstra
2019-10-17 19:07         ` Peter Zijlstra
2019-10-18 11:46           ` Douglas Raillard
2019-10-18 12:07             ` Peter Zijlstra
2019-10-18 14:44               ` Douglas Raillard
2019-10-18 15:15                 ` Vincent Guittot
2019-10-18 16:03                   ` Douglas Raillard
2019-10-18 15:20                 ` Vincent Guittot

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=65894424-3fdc-2b82-c84d-dac61aded5ea@arm.com \
    --to=douglas.raillard@arm.com \
    --cc=dh.han@samsung.com \
    --cc=dietmar.eggemann@arm.com \
    --cc=juri.lelli@redhat.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=patrick.bellasi@matbug.net \
    --cc=peterz@infradead.org \
    --cc=qperret@google.com \
    --cc=rjw@rjwysocki.net \
    --cc=vincent.guittot@linaro.org \
    --cc=viresh.kumar@linaro.org \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.