From: Arjan van de Ven <arjan@linux.intel.com>
To: riel@redhat.com, linux-pm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, rafael.j.wysocki@intel.com,
len.brown@intel.com, daniel.lezcano@linaro.org
Subject: Re: [PATCH 2/3] cpuidle,menu: use interactivity_req to disable polling
Date: Wed, 4 Nov 2015 08:01:38 -0800 [thread overview]
Message-ID: <563A2BE2.4090101@linux.intel.com> (raw)
In-Reply-To: <1446590059-18897-3-git-send-email-riel@redhat.com>
On 11/3/2015 2:34 PM, riel@redhat.com wrote:
> From: Rik van Riel <riel@redhat.com>
>
> The menu governor carefully figures out how much time we typically
> sleep for an estimated sleep interval, or whether there is a repeating
> pattern going on, and corrects that estimate for the CPU load.
>
> Then it proceeds to ignore that information when determining whether
> or not to consider polling. This is not a big deal on most x86 CPUs,
> which have very low C1 latencies, and the patch should not have any
> effect on those CPUs.
>
> However, certain CPUs (eg. Atom) have much higher C1 latencies, and
> it would be good to not waste performance and power on those CPUs if
> we are expecting a very low wakeup latency.
>
> Disable polling based on the estimated interactivity requirement, not
> on the time to the next timer interrupt.
>
good catch!
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
next prev parent reply other threads:[~2015-11-04 16:01 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-03 22:34 [PATCH 0/3] cpuidle: small improvements & fixes for menu governor (resend) riel
2015-11-03 22:34 ` [PATCH 1/3] cpuidle,x86: increase forced cut-off for polling to 20us riel
2015-11-04 16:00 ` Arjan van de Ven
2015-11-03 22:34 ` [PATCH 2/3] cpuidle,menu: use interactivity_req to disable polling riel
2015-11-04 16:01 ` Arjan van de Ven [this message]
2016-01-13 17:27 ` Sudeep Holla
2016-01-13 21:58 ` Rafael J. Wysocki
2016-01-13 22:07 ` Rafael J. Wysocki
2016-01-14 10:40 ` Sudeep Holla
2016-01-15 0:46 ` Rafael J. Wysocki
2016-01-14 10:33 ` Sudeep Holla
2015-11-03 22:34 ` [PATCH 3/3] cpuidle,menu: smooth out measured_us calculation riel
2015-11-04 16:02 ` Arjan van de Ven
2015-11-05 22:34 ` [PATCH 0/3] cpuidle: small improvements & fixes for menu governor (resend) Rafael J. Wysocki
2015-11-06 2:26 ` Rik van Riel
-- strict thread matches above, loose matches on Subject: below --
2015-10-28 22:46 [PATCH 0/3] cpuidle: small improvements & fixes for menu governor riel
2015-10-28 22:46 ` [PATCH 2/3] cpuidle,menu: use interactivity_req to disable polling riel
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=563A2BE2.4090101@linux.intel.com \
--to=arjan@linux.intel.com \
--cc=daniel.lezcano@linaro.org \
--cc=len.brown@intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pm@vger.kernel.org \
--cc=rafael.j.wysocki@intel.com \
--cc=riel@redhat.com \
/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).