From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751505Ab3BNFER (ORCPT ); Thu, 14 Feb 2013 00:04:17 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:48627 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750729Ab3BNFEP (ORCPT ); Thu, 14 Feb 2013 00:04:15 -0500 Message-ID: <1360818247.5374.300.camel@deadeye.wl.decadent.org.uk> Subject: Re: 3.2.38 most of the time has 100% cpu use reported From: Ben Hutchings To: tmhikaru@gmail.com Cc: linux-kernel@vger.kernel.org Date: Thu, 14 Feb 2013 05:04:07 +0000 In-Reply-To: <20130212050116.GA2146@roll> References: <1360160863.32217.30.camel@deadeye.wl.decadent.org.uk> <20130207173630.GA8355@roll> <20130208190819.GA16894@roll> <20130210151140.GA2307@roll> <20130212050116.GA2146@roll> Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-pzcN6ffP9rHXu9ycrd2T" X-Mailer: Evolution 3.4.4-1 Mime-Version: 1.0 X-SA-Exim-Connect-IP: 2001:470:1f08:1539:a11:96ff:fec6:70c4 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-pzcN6ffP9rHXu9ycrd2T Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable 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 reporti= ng > guidelines and try to make a proper bug report out of this. >=20 > [1.] One line summary of the problem: > 3.2.38 most of the time has 100% cpu use reported >=20 > [2.] Full description of the problem/report: > Reverse applying the patch for >=20 > [9a1f08a1a192f9177d7063d903773aed800b840f] drivers/firmware/dmi_scan.c: f= etch dmi version from SMBIOS if it exists >=20 > 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 t= his > further or whom I should contact. I'd like to help anyone who wants to f= ix > whatever went wrong, so please contact me. 'perf top' will tell you where the CPU is spending its time. Ben. --=20 Ben Hutchings We get into the habit of living before acquiring the habit of thinking. - Albert Camu= s --=-pzcN6ffP9rHXu9ycrd2T Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iQIVAwUAURxwR+e/yOyVhhEJAQo+xxAAvNSCXVmqUR8n2LK1BLj8vgPvFN68iiVq 0AVRwmc+D0j+M/dhCa/+eyNckTd4gkdTN+7w8k+F9Uc2s77VmtKAqUwWM9O5MN4L 2yXhd5IEx0Go3VM6FH7PpyBZH8wdgxRNZimTcQg2DbWv+JkngZzGGGcuJxetURTB SzkQt+nex/d3Wdy5pBt6QJt6r2St9aEXrUTpe/NLUiSs8I3VEWsQWeAe3P0fQO65 M7K/L4uIjJ6ujsPnVUh0UPSuo5hg1s0m7DM5ZAmWm9ZAOTW1PuyKWDmirn9yDYCW Zcdo+y5umqQAjRJ9EllCcnZJi6XjrHNrhuHAwxxdunVxzWT51VkHEAvzHNCtoWD3 4kfPsfUBtJfrbVP8OtCCt//FUGQcmEAyTqUq5y5GfElTsKz4AY6EM0P3JobSsVwI YkuxxOtn1rTvmFodwWcH/6zoNmw87dtBl/9vHuDxccrHaU/MqaICbioJIot6qFGa 7a7YUNu5lXzcWFOdbKUTwLYi4gZkgHl1/Q1Fyp0mEaVQgHEP95H2zKyeUtZqVp0+ 093ZoZcB7Vzd18rIZMqpy27oUWG2r7MMubUF2GlS42AGD+Q2c68QzAh94ZV9ZASV 82n5K8KwqUQ34o9ztlvUQPihS88CCoDQuB2NPtEVCwAgJPDGGKC7qVOLfBRVq2MF uv2DRlCqRfo= =bcmV -----END PGP SIGNATURE----- --=-pzcN6ffP9rHXu9ycrd2T--