Linux-PM Archive on lore.kernel.org
 help / color / 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
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 index

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-11 13:44 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 publically 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

Linux-PM Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-pm/0 linux-pm/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-pm linux-pm/ https://lore.kernel.org/linux-pm \
		linux-pm@vger.kernel.org
	public-inbox-index linux-pm

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-pm


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git