All of lore.kernel.org
 help / color / mirror / Atom feed
From: Peter Zijlstra <peterz@infradead.org>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Steve Muckle <steve.muckle@linaro.org>,
	Vincent Guittot <vincent.guittot@linaro.org>,
	Linux PM list <linux-pm@vger.kernel.org>,
	Juri Lelli <juri.lelli@arm.com>,
	ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
	Viresh Kumar <viresh.kumar@linaro.org>,
	Michael Turquette <mturquette@baylibre.com>,
	Ingo Molnar <mingo@redhat.com>
Subject: Re: [PATCH 6/6] cpufreq: schedutil: New governor based on scheduler utilization data
Date: Thu, 10 Mar 2016 09:43:31 +0100	[thread overview]
Message-ID: <20160310084331.GO6344@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <CAJZ5v0iKn4dT4ta6WaEcPbdYmA7P08=bmKU+dwcMx+Msk7WRFg@mail.gmail.com>

On Thu, Mar 10, 2016 at 12:28:52AM +0100, Rafael J. Wysocki wrote:
> > [ I would not have chosen (1 + 1/n), but lets stick to that ]
> 
> Well, what would you choose then? :-)

1/p ; 0 < p < 1

or so. Where p then represents the percentile threshold where you want
to bump to the next freq.

> I think that should be
> 
>   next_freq = (1 + 1/n) * max_freq * util / max
> 
> (where max is the second argument of cpufreq_update_util) or the
> dimensions on both sides don't match.

Well yes, but so far we were treating util (and util_raw) as 0 < u < 1,
values, so already normalized against max.

But yes..

> > if we substitute (2) into (3) we get:
> >
> >                   = (1 + 1/n) * max_freq * util_raw * current_freq / max_freq
> >                   = (1 + 1/n) * current_freq * util_raw (4)
> >
> > Which gets you two formula with the same general behaviour. As (2) is
> > the only approximation of (1) we can make.
> 
> OK
> 
> So since utilization is not frequency invariant in the current
> mainline (or linux-next for that matter) AFAIC, I'm going to use the
> following in the next version of the schedutil patch series:
> 
>   next_freq = 1.25 * current_freq * util_raw / max
> 
> where util_raw and max are what I get from cpufreq_update_util().
> 
> 1.25 is for the 80% tipping point which I think is reasonable.

OK.

  parent reply	other threads:[~2016-03-10  8:43 UTC|newest]

Thread overview: 159+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-03-02  1:56 [PATCH 0/6] cpufreq: schedutil governor Rafael J. Wysocki
2016-03-02  2:04 ` [PATCH 1/6] cpufreq: Reduce cpufreq_update_util() overhead a bit Rafael J. Wysocki
2016-03-03  5:48   ` Viresh Kumar
2016-03-03 11:47   ` Juri Lelli
2016-03-03 13:04     ` Peter Zijlstra
2016-03-02  2:05 ` [PATCH 2/6][Resend] cpufreq: acpi-cpufreq: Make read and write operations more efficient Rafael J. Wysocki
2016-03-02  2:08 ` [PATCH 3/6] cpufreq: governor: New data type for management part of dbs_data Rafael J. Wysocki
2016-03-03  5:53   ` Viresh Kumar
2016-03-03 19:26     ` Rafael J. Wysocki
2016-03-04  5:49       ` Viresh Kumar
2016-03-02  2:10 ` [PATCH 4/6] cpufreq: governor: Move abstract gov_tunables code to a seperate file Rafael J. Wysocki
2016-03-03  6:03   ` Viresh Kumar
2016-03-02  2:12 ` [PATCH 5/6] cpufreq: Support for fast frequency switching Rafael J. Wysocki
2016-03-03  6:00   ` Viresh Kumar
2016-03-04  2:15     ` Rafael J. Wysocki
2016-03-03 11:16   ` Peter Zijlstra
2016-03-03 20:56     ` Rafael J. Wysocki
2016-03-03 21:12       ` Peter Zijlstra
2016-03-03 11:18   ` Peter Zijlstra
2016-03-03 19:39     ` Rafael J. Wysocki
2016-03-02  2:27 ` [PATCH 6/6] cpufreq: schedutil: New governor based on scheduler utilization data Rafael J. Wysocki
2016-03-02 17:10   ` Vincent Guittot
2016-03-02 17:58     ` Rafael J. Wysocki
2016-03-02 22:49       ` Rafael J. Wysocki
2016-03-03 12:20         ` Peter Zijlstra
2016-03-03 12:32           ` Juri Lelli
2016-03-03 16:24           ` Rafael J. Wysocki
2016-03-03 16:37             ` Peter Zijlstra
2016-03-03 16:47               ` Peter Zijlstra
2016-03-04  1:14                 ` Rafael J. Wysocki
2016-03-03 16:55               ` Juri Lelli
2016-03-03 16:56                 ` Peter Zijlstra
2016-03-03 17:14                   ` Juri Lelli
2016-03-03 14:01         ` Vincent Guittot
2016-03-03 15:38           ` Peter Zijlstra
2016-03-03 16:28             ` Peter Zijlstra
2016-03-03 16:42               ` Peter Zijlstra
2016-03-03 17:28               ` Dietmar Eggemann
2016-03-03 18:26                 ` Peter Zijlstra
2016-03-03 19:14                   ` Dietmar Eggemann
2016-03-08 13:09                   ` Peter Zijlstra
2016-03-03 18:58               ` Rafael J. Wysocki
2016-03-03 13:07       ` Vincent Guittot
2016-03-03 20:06         ` Steve Muckle
2016-03-03 20:20           ` Rafael J. Wysocki
2016-03-03 21:37             ` Steve Muckle
2016-03-07  2:41               ` Rafael J. Wysocki
2016-03-08 11:27                 ` Peter Zijlstra
2016-03-08 18:00                   ` Rafael J. Wysocki
2016-03-08 19:26                     ` Peter Zijlstra
2016-03-08 20:05                       ` Rafael J. Wysocki
2016-03-09 10:15                         ` Juri Lelli
2016-03-09 23:41                           ` Rafael J. Wysocki
2016-03-10  4:30                             ` Juri Lelli
2016-03-10 21:01                               ` Rafael J. Wysocki
2016-03-10 23:19                             ` Michael Turquette
2016-03-10 23:19                               ` Michael Turquette
2016-03-09 16:39                         ` Peter Zijlstra
2016-03-09 23:28                           ` Rafael J. Wysocki
2016-03-10  3:44                             ` Vincent Guittot
2016-03-10 10:07                               ` Peter Zijlstra
2016-03-10 10:26                                 ` Vincent Guittot
     [not found]                                 ` <CAKfTPtCbjgbJn+68NJPCnmPFtcHD0wGmZRYaw37zSqPXNpo_Uw@mail.gmail.com>
2016-03-10 10:30                                   ` Peter Zijlstra
2016-03-10 10:56                                     ` Peter Zijlstra
2016-03-10 22:28                                       ` Rafael J. Wysocki
2016-03-10  8:43                             ` Peter Zijlstra [this message]
2016-03-04  2:56 ` [PATCH v2 0/10] cpufreq: schedutil governor Rafael J. Wysocki
2016-03-04  2:58   ` [PATCH v2 1/10] cpufreq: Reduce cpufreq_update_util() overhead a bit Rafael J. Wysocki
2016-03-09 12:39     ` Peter Zijlstra
2016-03-09 14:17       ` Rafael J. Wysocki
2016-03-09 15:29         ` Peter Zijlstra
2016-03-09 21:35           ` Rafael J. Wysocki
2016-03-10  9:19             ` Peter Zijlstra
2016-03-04  2:59   ` [PATCH v2 2/10][Resend] cpufreq: acpi-cpufreq: Make read and write operations more efficient Rafael J. Wysocki
2016-03-04  3:01   ` [PATCH v2 3/10] cpufreq: governor: New data type for management part of dbs_data Rafael J. Wysocki
2016-03-04  5:52     ` Viresh Kumar
2016-03-04  3:03   ` [PATCH v2 4/10] cpufreq: governor: Move abstract gov_attr_set code to seperate file Rafael J. Wysocki
2016-03-04  5:52     ` Viresh Kumar
2016-03-04  3:05   ` [PATCH v2 5/10] cpufreq: Move governor attribute set headers to cpufreq.h Rafael J. Wysocki
2016-03-04  5:53     ` Viresh Kumar
2016-03-04  3:07   ` [PATCH v2 6/10] cpufreq: Support for fast frequency switching Rafael J. Wysocki
2016-03-04 22:18     ` Steve Muckle
2016-03-04 22:32       ` Rafael J. Wysocki
2016-03-04 22:40         ` Rafael J. Wysocki
2016-03-04 23:18           ` Rafael J. Wysocki
2016-03-04 23:56             ` Steve Muckle
2016-03-05  0:18               ` Rafael J. Wysocki
2016-03-05 11:58                 ` Ingo Molnar
2016-03-05 16:49             ` Peter Zijlstra
2016-03-06  2:17               ` Rafael J. Wysocki
2016-03-07  8:00                 ` Peter Zijlstra
2016-03-07 13:15                   ` Rafael J. Wysocki
2016-03-07 13:32                     ` Peter Zijlstra
2016-03-07 13:42                       ` Rafael J. Wysocki
2016-03-04 22:58         ` Rafael J. Wysocki
2016-03-04 23:59           ` Steve Muckle
2016-03-04  3:12   ` [PATCH v2 7/10] cpufreq: Rework the scheduler hooks for triggering updates Rafael J. Wysocki
2016-03-04  3:14   ` [PATCH v2 8/10] cpufreq: Move scheduler-related code to the sched directory Rafael J. Wysocki
2016-03-04  3:18   ` [PATCH v2 9/10] cpufreq: sched: Re-introduce cpufreq_update_util() Rafael J. Wysocki
2016-03-04 10:50     ` Juri Lelli
2016-03-04 12:58       ` Rafael J. Wysocki
2016-03-04 13:30     ` [PATCH v3 " Rafael J. Wysocki
2016-03-04 21:21       ` Steve Muckle
2016-03-04 21:27         ` Rafael J. Wysocki
2016-03-04 21:36           ` Rafael J. Wysocki
2016-03-04  3:35   ` [PATCH v2 10/10] cpufreq: schedutil: New governor based on scheduler utilization data Rafael J. Wysocki
2016-03-04 11:26     ` Juri Lelli
2016-03-04 13:19       ` Rafael J. Wysocki
2016-03-04 15:56       ` Srinivas Pandruvada
2016-03-08  2:23   ` [PATCH v3 0/7] cpufreq: schedutil governor Rafael J. Wysocki
2016-03-08  2:25     ` [PATCH v3 1/7][Resend] cpufreq: Rework the scheduler hooks for triggering updates Rafael J. Wysocki
2016-03-09 13:41       ` Peter Zijlstra
2016-03-09 14:02         ` Rafael J. Wysocki
2016-03-08  2:26     ` [PATCH v3 2/7][Resend] cpufreq: Move scheduler-related code to the sched directory Rafael J. Wysocki
2016-03-08  2:28     ` [PATCH v3 3/7][Resend] cpufreq: governor: New data type for management part of dbs_data Rafael J. Wysocki
2016-03-08  2:29     ` [PATCH v3 4/7][Resend] cpufreq: governor: Move abstract gov_attr_set code to seperate file Rafael J. Wysocki
2016-03-08  2:38     ` [PATCH v3 5/7] cpufreq: Support for fast frequency switching Rafael J. Wysocki
2016-03-08  2:41     ` [PATCH v3 6/7] cpufreq: sched: Re-introduce cpufreq_update_util() Rafael J. Wysocki
2016-03-08  2:50     ` [PATCH v3 7/7] cpufreq: schedutil: New governor based on scheduler utilization data Rafael J. Wysocki
2016-03-16 14:41     ` [PATCH v4 0/7] cpufreq: schedutil governor Rafael J. Wysocki
2016-03-16 14:43       ` [PATCH v4 1/7] cpufreq: sched: Helpers to add and remove update_util hooks Rafael J. Wysocki
2016-03-16 14:44       ` [PATCH v4 2/7] cpufreq: governor: New data type for management part of dbs_data Rafael J. Wysocki
2016-03-16 14:45       ` [PATCH v4 3/7] cpufreq: governor: Move abstract gov_attr_set code to seperate file Rafael J. Wysocki
2016-03-16 14:46       ` [PATCH v4 4/7] cpufreq: Move governor attribute set headers to cpufreq.h Rafael J. Wysocki
2016-03-16 14:47       ` [PATCH v4 5/7] cpufreq: Move governor symbols " Rafael J. Wysocki
2016-03-16 14:52       ` [PATCH v4 6/7] cpufreq: Support for fast frequency switching Rafael J. Wysocki
2016-03-16 15:35         ` Peter Zijlstra
2016-03-16 16:58           ` Rafael J. Wysocki
2016-03-16 15:43         ` Peter Zijlstra
2016-03-16 16:58           ` Rafael J. Wysocki
2016-03-16 14:59       ` [PATCH v4 7/7] cpufreq: schedutil: New governor based on scheduler utilization data Rafael J. Wysocki
2016-03-16 17:35         ` Peter Zijlstra
2016-03-16 21:42           ` Rafael J. Wysocki
2016-03-16 17:36         ` Peter Zijlstra
2016-03-16 21:34           ` Rafael J. Wysocki
2016-03-16 17:52         ` Peter Zijlstra
2016-03-16 21:38           ` Rafael J. Wysocki
2016-03-16 22:39             ` Peter Zijlstra
2016-03-16 17:53         ` Peter Zijlstra
2016-03-16 21:48           ` Rafael J. Wysocki
2016-03-16 18:14         ` Peter Zijlstra
2016-03-16 21:38           ` Rafael J. Wysocki
2016-03-16 22:40             ` Peter Zijlstra
2016-03-16 22:53               ` Rafael J. Wysocki
2016-03-16 15:27       ` [PATCH v4 0/7] cpufreq: schedutil governor Peter Zijlstra
2016-03-16 16:20         ` Rafael J. Wysocki
2016-03-16 23:51       ` [PATCH v5 6/7][Update] cpufreq: Support for fast frequency switching Rafael J. Wysocki
2016-03-17 11:35         ` Juri Lelli
2016-03-17 11:40           ` Peter Zijlstra
2016-03-17 11:48             ` Juri Lelli
2016-03-17 12:53               ` Rafael J. Wysocki
2016-03-17  0:01       ` [PATCH v5 7/7][Update] cpufreq: schedutil: New governor based on scheduler utilization data Rafael J. Wysocki
2016-03-17 11:30         ` Juri Lelli
2016-03-17 12:54           ` Rafael J. Wysocki
2016-03-17 11:36         ` Peter Zijlstra
2016-03-17 12:54           ` Rafael J. Wysocki
2016-03-17 15:54       ` [PATCH v6 6/7][Update] cpufreq: Support for fast frequency switching Rafael J. Wysocki
2016-03-17 16:01       ` [PATCH v6 7/7][Update] cpufreq: schedutil: New governor based on scheduler utilization data Rafael J. Wysocki
2016-03-18 12:34         ` Patrick Bellasi

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=20160310084331.GO6344@twins.programming.kicks-ass.net \
    --to=peterz@infradead.org \
    --cc=juri.lelli@arm.com \
    --cc=linux-acpi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=mturquette@baylibre.com \
    --cc=rafael@kernel.org \
    --cc=rjw@rjwysocki.net \
    --cc=srinivas.pandruvada@linux.intel.com \
    --cc=steve.muckle@linaro.org \
    --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.