public inbox for linux-kernel@vger.kernel.org
 help / color / mirror / Atom feed
From: Matthew Garrett <mjg59@srcf.ucam.org>
To: Len Brown <lenb@kernel.org>
Cc: Zdenek Kabelac <zdenek.kabelac@gmail.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	cpufreq@vger.kernel.org
Subject: Re: Perfomance governor is still changing frequency
Date: Tue, 23 Dec 2008 17:56:00 +0000	[thread overview]
Message-ID: <20081223175600.GB17426@srcf.ucam.org> (raw)
In-Reply-To: <alpine.LFD.2.00.0812151242430.16823@localhost.localdomain>

On Mon, Dec 15, 2008 at 12:59:15PM -0500, Len Brown wrote:

> and that will tell us if turbo is related to your
> occasional obervance of low-frequency-mode.

We've observed this on certain other pieces of modern Intel hardware - 
the best hypothesis we've been able to come up with is that if the msr 
read is the first instruction run on the core when it's previously been 
in a deep C state, the low-clock speed is reported. However, some 
Thinkpads will also automatically limit their speed for thermal reasons.

-- 
Matthew Garrett | mjg59@srcf.ucam.org

  reply	other threads:[~2008-12-23 17:56 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2008-12-15 13:15 Perfomance governor is still changing frequency Zdenek Kabelac
2008-12-15 17:59 ` Len Brown
2008-12-23 17:56   ` Matthew Garrett [this message]
2008-12-15 20:53 ` Tim Blechmann

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=20081223175600.GB17426@srcf.ucam.org \
    --to=mjg59@srcf.ucam.org \
    --cc=cpufreq@vger.kernel.org \
    --cc=lenb@kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=zdenek.kabelac@gmail.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