From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751872Ab2DCH1j (ORCPT ); Tue, 3 Apr 2012 03:27:39 -0400 Received: from mondschein.lichtvoll.de ([194.150.191.11]:49769 "EHLO mail.lichtvoll.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750865Ab2DCH1i convert rfc822-to-8bit (ORCPT ); Tue, 3 Apr 2012 03:27:38 -0400 From: Martin Steigerwald To: "Srivatsa S. Bhat" Subject: Re: [REGRESSION] NMI received for unknown reason 3c on CPU 0, strange powersaving mode? Date: Tue, 3 Apr 2012 09:27:36 +0200 User-Agent: KMail/1.13.7 (Linux/3.3.0-trunk-amd64; KDE/4.7.4; x86_64; ; ) Cc: linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, a.p.zijlstra@chello.nl, stern@rowland.harvard.edu, rjw@sisk.pl, pavel@ucw.cz References: <201203301304.49708.Martin@lichtvoll.de> <4F7987D0.3090106@linux.vnet.ibm.com> (sfid-20120402_143911_704229_5D7541F7) In-Reply-To: <4F7987D0.3090106@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 8BIT Message-Id: <201204030927.36606.Martin@lichtvoll.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Montag, 2. April 2012 schrieb Srivatsa S. Bhat: > On 03/30/2012 04:34 PM, Martin Steigerwald wrote: > > Hi! > > > > Since some time I am seeing things like > > > > Message from syslogd@merkaba at Mar 30 00:29:30 ... > > > > kernel:[49074.294260] Uhhuh. NMI received for unknown reason 3c on > > CPU 0. > > > > Message from syslogd@merkaba at Mar 30 00:29:30 ... > > > > kernel:[49074.294263] Do you have a strange power saving mode > > enabled? > > > > Message from syslogd@merkaba at Mar 30 00:29:30 ... > > > > kernel:[49074.294264] Dazed and confused, but trying to continue > > > > on resume after in-kernel hibernation. > > Do you see this after suspend-to-ram too? No. > > I do not see any trace of it in syslog, kern.log or dmesg. > > > > From the timestemp it seems that these messages are issued shortly > > before I send the laptop to hibernation last night. > > > > > > I am using a ThinkPad T520 with Intel(R) Core(TM) i5-2520M CPU @ > > 2.50GHz and Sandybridge graphics. > > > > I am not exactly sure since when it happens, cause I basically > > ignored it for quite some time. Might be some 3.2 kernel where it > > started, maybe even the first 3.2 kernel I had. Currently I am > > using: > > > > martin@merkaba:~> cat /proc/version > > Linux version 3.3.0-trunk-amd64 (Debian 3.3-1~experimental.1) > > (debian- kernel@lists.debian.org) (gcc version 4.6.3 (Debian > > 4.6.3-1) ) #1 SMP Thu Mar 22 18:02:10 UTC 2012 > > > > Since I am quite sure I didn´t see this with the first kernel I used > > on this machine, which was a 2.6.39 if I remember correctly, I > > consider this to be a regression for now. > > > > > > I did not see any other strange effects, only this message. > > > > > > When searching for it I see quite some references¹. But what I looked > > at seemed to either quite old or different in that the machine was > > frozen then. > > There was once such a bug report and commit 144060fee (perf: Add PM > notifiers to fix CPU hotplug races) tried to fix it, however it didn't > work out IIRC. > > Can you please try out the pm-test framework and let us know in which > phase this message is encountered? > Documentation/power/basic-pm-debugging.txt > > 1. Recompile the kernel with CONFIG_PM_DEBUG=y Luckily I have this already. martin@merkaba:~> grep CONFIG_PM_DEBUG /boot/config-3.3.0-trunk-amd64 CONFIG_PM_DEBUG=y > 2. # cat /sys/power/pm_test > 3. # echo > /sys/power/pm_test > Use the values from the list given in step 2. > From freezer to core, it is increasing depth of suspend phase. > 4. # echo mem > /sys/power/state (for suspend-to-ram) > or echo disk > /sys/power/state (for suspend-to-disk) I understand it that you want me to do step 4 for each of the values from step 3. If not so, please tell me. Now I send this out, before I start my tests. ;) Ciao, -- Martin 'Helios' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7