mirror of https://lore.kernel.org/lkml/
 help / color / mirror / Atom feed
From: "Rafael J. Wysocki" <rjw@rjwysocki.net>
To: Daniel Lezcano <daniel.lezcano@linaro.org>,
	"Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: linux-pm@vger.kernel.org, Todd Kjos <tkjos@google.com>,
	Joel Fernandes <joelaf@google.com>,
	Colin Cross <ccross@android.com>,
	Ramesh Thomas <ramesh.thomas@intel.com>,
	Alex Shi <alex.shi@linaro.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH RFC] cpuidle/drivers/menu: Remove get_loadavg in the performance multiplier
Date: Wed, 03 Oct 2018 10:58:16 +0200	[thread overview]
Message-ID: <4200780.ZjVhNjpZ67@aspire.rjw.lan> (raw)
In-Reply-To: <1537868328-13405-1-git-send-email-daniel.lezcano@linaro.org>

On Tuesday, September 25, 2018 11:38:44 AM CEST Daniel Lezcano wrote:
> The function get_loadavg() returns almost always zero. To be more
> precise, statistically speaking for a total of 1023379 times passing
> to the function, the load is equal to zero 1020728 times, greater than
> 100, 610 times, the remaining is between 0 and 5.
> 
> I'm putting in question this metric. Is it worth to keep it?

The honest answer is that I'm not sure.

Using the CPU load for driving idle state selection is questionable in general
(there need not be any connection between the two in principle) and this
particular function is questionable either.  If it really makes no difference
in addition to that, then yes it would be good to get rid of it.

That said it looks like that may be quite workload-dependent, so maybe there
are workloads where it does make a difference?  Like networking or similar?

Thanks,
Rafael


  reply	other threads:[~2018-10-03  9:01 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-09-25  9:38 Daniel Lezcano
2018-10-03  8:58 ` Rafael J. Wysocki [this message]
2018-10-03 10:25   ` Daniel Lezcano
2018-10-03 11:09     ` Rafael J. Wysocki
2018-10-03 13:05       ` Daniel Lezcano

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=4200780.ZjVhNjpZ67@aspire.rjw.lan \
    --to=rjw@rjwysocki.net \
    --cc=alex.shi@linaro.org \
    --cc=ccross@android.com \
    --cc=daniel.lezcano@linaro.org \
    --cc=joelaf@google.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=peterz@infradead.org \
    --cc=ramesh.thomas@intel.com \
    --cc=tkjos@google.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

all inboxes | Powered by JetHome®