linux-pm.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Viresh Kumar <viresh.kumar@linaro.org>
To: rjw@sisk.pl
Cc: cpufreq@vger.kernel.org, linux-pm@vger.kernel.org,
	linux-kernel@vger.kernel.org, linaro-kernel@lists.linaro.org,
	robin.randhawa@arm.com, Steve.Bannister@arm.com,
	Liviu.Dudau@arm.com, charles.garcia-tobin@arm.com,
	rickard.andersson@stericsson.com, fabio.baltieri@linaro.org,
	tj@kernel.org, Viresh Kumar <viresh.kumar@linaro.org>
Subject: [PATCH V2 0/2] cpufreq: governors: Avoid unnecessary per cpu timer interrupts
Date: Mon,  4 Mar 2013 15:47:22 +0800	[thread overview]
Message-ID: <cover.1362382746.git.viresh.kumar@linaro.org> (raw)

Following patch has introduced per cpu timers or works for ondemand and
conservative governors.

        commit 2abfa876f1117b0ab45f191fb1f82c41b1cbc8fe
        Author: Rickard Andersson <rickard.andersson@stericsson.com>
        Date:   Thu Dec 27 14:55:38 2012 +0000

            cpufreq: handle SW coordinated CPUs

This causes additional unnecessary interrupts on all cpus when the load is
recently evaluated by any other cpu. i.e. When load is recently evaluated by cpu
x, we don't really need any other cpu to evaluate this load again for the next
sampling_rate time.

Some sort of code is present to avoid that but we are still getting timer
interrupts for all cpus. A good way of avoiding this would be to modify delays
for all cpus (policy->cpus) whenever any cpu has evaluated load.

This patchset tries to fix this issue.

These patches are applied here:

http://git.linaro.org/gitweb?p=people/vireshk/linux.git;a=shortlog;h=refs/heads/for-3.10

V1->V2:
- Dropped Workqueue modifications and use system_wq directly.

Viresh Kumar (2):
  cpufreq: ondemand: Don't update sample_type if we don't evaluate load
    again
  cpufreq: governors: Avoid unnecessary per cpu timer interrupts

 drivers/cpufreq/cpufreq_conservative.c |  8 ++++---
 drivers/cpufreq/cpufreq_governor.c     | 39 ++++++++++++++++++++++++----------
 drivers/cpufreq/cpufreq_governor.h     |  2 ++
 drivers/cpufreq/cpufreq_ondemand.c     | 34 ++++++++++++++---------------
 4 files changed, 52 insertions(+), 31 deletions(-)

-- 
1.7.12.rc2.18.g61b472e


             reply	other threads:[~2013-03-04  7:47 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-03-04  7:47 Viresh Kumar [this message]
2013-03-04  7:47 ` [PATCH V2 1/2] cpufreq: ondemand: Don't update sample_type if we don't evaluate load again Viresh Kumar
2013-03-04  7:47 ` [PATCH V2 2/2] cpufreq: governors: Avoid unnecessary per cpu timer interrupts Viresh Kumar

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=cover.1362382746.git.viresh.kumar@linaro.org \
    --to=viresh.kumar@linaro.org \
    --cc=Liviu.Dudau@arm.com \
    --cc=Steve.Bannister@arm.com \
    --cc=charles.garcia-tobin@arm.com \
    --cc=cpufreq@vger.kernel.org \
    --cc=fabio.baltieri@linaro.org \
    --cc=linaro-kernel@lists.linaro.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=rickard.andersson@stericsson.com \
    --cc=rjw@sisk.pl \
    --cc=robin.randhawa@arm.com \
    --cc=tj@kernel.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 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).