From: Andi Kleen <andi@firstfloor.org>
To: Stephane Eranian <eranian@hpl.hp.com>
Cc: Andi Kleen <andi@firstfloor.org>,
linux-kernel@vger.kernel.org, perfmon@napali.hpl.hp.com
Subject: Re: exposing FSB clock speed in /sys
Date: Sat, 31 Mar 2007 12:02:09 +0200 [thread overview]
Message-ID: <20070331100209.GA17761@one.firstfloor.org> (raw)
In-Reply-To: <20070331081832.GB17535@frankl.hpl.hp.com>
> I am not interested in older processors, but I think for all recent Intel
> processors, there is a fairly simple algorithm to get the frequency using
> a couple of MSRs (including MSR_IA32_EBL_CR_POWERON or MSR_FSB_FREQ).
Hmm, maybe make it an own driver that creates the sysfs entries somewhere.
I don't think it's useful enough for the main kernel.
But what happens during power saving that may lower the frequency?
Wouldn't you need update events for that? That might complicate it.
>
> Don't we already have /sys entries that exits only for certain processors
> or platforms?
Yes.
> I think the Opteron have HYPERTRANSPORT-related events which could be used
> to obtain similar metrics.
Yes, but you usually don't need the frequency.
-Andi
next prev parent reply other threads:[~2007-03-31 10:02 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-03-30 15:39 exposing FSB clock speed in /sys Stephane Eranian
2007-03-30 15:49 ` Arjan van de Ven
2007-03-30 18:20 ` Alan Cox
2007-03-30 18:44 ` [perfmon] " Martin Cracauer
2007-03-31 2:31 ` Andi Kleen
2007-03-31 8:18 ` Stephane Eranian
2007-03-31 10:02 ` Andi Kleen [this message]
2007-04-02 16:14 ` Lennart Sorensen
2007-04-02 20:52 ` Stephane Eranian
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=20070331100209.GA17761@one.firstfloor.org \
--to=andi@firstfloor.org \
--cc=eranian@hpl.hp.com \
--cc=linux-kernel@vger.kernel.org \
--cc=perfmon@napali.hpl.hp.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