From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261173AbVFCHe2 (ORCPT ); Fri, 3 Jun 2005 03:34:28 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261177AbVFCHe2 (ORCPT ); Fri, 3 Jun 2005 03:34:28 -0400 Received: from www.tuxrocks.com ([64.62.190.123]:49426 "EHLO tuxrocks.com") by vger.kernel.org with ESMTP id S261173AbVFCHeU (ORCPT ); Fri, 3 Jun 2005 03:34:20 -0400 Message-ID: <42A006E8.9000601@tuxrocks.com> Date: Fri, 03 Jun 2005 01:29:44 -0600 From: Frank Sorenson User-Agent: Mozilla Thunderbird 1.0.2 (X11/20050317) X-Accept-Language: en-us, en MIME-Version: 1.0 To: john stultz CC: Andrew Morton , lkml , Tim Schmielau , George Anzinger , albert@users.sourceforge.net, Ulrich Windl , Christoph Lameter , Dominik Brodowski , David Mosberger , Andi Kleen , paulus@samba.org, schwidefsky@de.ibm.com, keith maanthey , Chris McDermott , Max Asbock , mahuja@us.ibm.com, Nishanth Aravamudan , Darren Hart , "Darrick J. Wong" , Anton Blanchard , donf@us.ibm.com, mpm@selenic.com, benh@kernel.crashing.org Subject: Re: [PATCH 1/4] new timeofday core subsystem (v. B1) References: <1117667378.6801.80.camel@cog.beaverton.ibm.com> In-Reply-To: <1117667378.6801.80.camel@cog.beaverton.ibm.com> X-Enigmail-Version: 0.91.0.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 john stultz wrote: > Andrew, All, > I'm just re-spinning this to resolve a conflict w/ the CPUFREQ changes > Linus accepted last night. John, I have found an issue with these TOD subsystem patches, and I think it's only an issue on systems that use CPUFREQ. Whenever the frequency changes, at least some portions of the kernel get confused about their notion of time. Here are some example entries from my syslog: Jun 3 00:33:40 moebius kernel: [ 145.023201] cpufreq-core: target for CPU 0: 800000 kHz, relation 0 Jun 3 00:33:47 moebius kernel: [ 114.838909] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0 Jun 3 00:33:47 moebius kernel: [ 114.838977] freq-table: request for target 1000000 kHz (relation: 0) for cpu 0 Jun 3 00:33:47 moebius kernel: [ 92.161872] codec_semaphore: semaphore is not ready [0x1][0x700300] Jun 3 00:33:52 moebius kernel: [ 97.433279] cpufreq-core: target for CPU 0: 1200000 kHz, relation 0 Jun 3 00:33:58 moebius kernel: [ 66.352233] cpufreq-core: target for CPU 0: 1400000 kHz, relation 0 Jun 3 00:34:08 moebius kernel: [ 85.547260] cpufreq-core: target for CPU 0: 1200000 kHz, relation 0 Jun 3 00:34:16 moebius kernel: [ 211.791738] cpufreq-core: target for CPU 0: 800000 kHz, relation 0 Jun 3 00:34:27 moebius kernel: [ 112.941898] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0 Jun 3 00:34:31 moebius kernel: [ 231.793121] cpufreq-core: target for CPU 0: 800000 kHz, relation 0 Jun 3 00:34:41 moebius kernel: [ 147.122593] cpufreq-core: target for CPU 0: 1200000 kHz, relation 0 Jun 3 00:34:42 moebius kernel: [ 123.906802] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0 Jun 3 00:34:46 moebius kernel: [ 251.342116] cpufreq-core: target for CPU 0: 800000 kHz, relation 0 Jun 3 00:34:51 moebius kernel: [ 192.985214] cpufreq-core: target for CPU 0: 1000000 kHz, relation 0 The printk times are taken from sched_clock(), which now varies depending on the cpu frequency. Without these patches, the printk times appear to consistently increase at the right rate. I'm not sure what other portions of the kernel are affected by this (watchdogs firing, or other issues?). Thanks, Frank - -- Frank Sorenson - KD7TZK Systems Manager, Computer Science Department Brigham Young University frank@tuxrocks.com -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.6 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org iD8DBQFCoAboaI0dwg4A47wRAmWsAJsHJ3sYtUqXKqjnualA3JTOih9RwACeIulR CCKYtqdZ/096knyiwZf6X44= =SjAZ -----END PGP SIGNATURE-----