linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Ben Hutchings <ben@decadent.org.uk>
To: tmhikaru@gmail.com
Cc: linux-kernel@vger.kernel.org
Subject: Re: 3.2.38 most of the time has 100% cpu use reported
Date: Thu, 14 Feb 2013 05:04:07 +0000	[thread overview]
Message-ID: <1360818247.5374.300.camel@deadeye.wl.decadent.org.uk> (raw)
In-Reply-To: <20130212050116.GA2146@roll>

[-- Attachment #1: Type: text/plain, Size: 1420 bytes --]

On Tue, 2013-02-12 at 00:01 -0500, tmhikaru@gmail.com wrote:
> 	Okay, I finally have located the patch causing this bizzare problem
> for me. Before I discuss it, I'm going to drag out the kernel bug reporting
> guidelines and try to make a proper bug report out of this.
> 
> [1.] One line summary of the problem:
> 3.2.38 most of the time has 100% cpu use reported
> 
> [2.] Full description of the problem/report:
> Reverse applying the patch for
> 
> [9a1f08a1a192f9177d7063d903773aed800b840f] drivers/firmware/dmi_scan.c: fetch dmi version from SMBIOS if it exists
> 
> on top of a clean 3.2.38 tree makes the problem go away.
[...]
> I have to admit I have no idea what the patch I'm reversing actually does,

It changes how we look for the version of a BIOS interface (DMI or
SMBIOS).  All the code that it touches, and the version number variable,
are discarded after boot and therefore can have very limited effect on
what happens later!

> what the cpu is doing when it's stuck at 100%, nor how I would diagnose this
> further or whom I should contact.  I'd like to help anyone who wants to fix
> whatever went wrong, so please contact me.

'perf top' will tell you where the CPU is spending its time.

Ben.

-- 
Ben Hutchings
We get into the habit of living before acquiring the habit of thinking.
                                                              - Albert Camus

[-- Attachment #2: This is a digitally signed message part --]
[-- Type: application/pgp-signature, Size: 828 bytes --]

  reply	other threads:[~2013-02-14  5:04 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-02-06 14:27 Linux 3.2.38 Ben Hutchings
2013-02-06 14:34 ` Ben Hutchings
2013-02-07 17:36 ` tmhikaru
2013-02-08  1:11   ` Ben Hutchings
2013-02-08 14:27     ` Roland Eggner
2013-02-08 19:08   ` tmhikaru
2013-02-10 15:11     ` tmhikaru
2013-02-12  5:01       ` 3.2.38 most of the time has 100% cpu use reported tmhikaru
2013-02-14  5:04         ` Ben Hutchings [this message]
2013-02-16  3:23           ` tmhikaru
2013-02-16  5:18             ` Ben Hutchings
2013-02-16  6:42               ` tmhikaru

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=1360818247.5374.300.camel@deadeye.wl.decadent.org.uk \
    --to=ben@decadent.org.uk \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tmhikaru@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;
as well as URLs for NNTP newsgroup(s).