From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752935Ab2DCJpp (ORCPT ); Tue, 3 Apr 2012 05:45:45 -0400 Received: from e28smtp01.in.ibm.com ([122.248.162.1]:33813 "EHLO e28smtp01.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751394Ab2DCJpo (ORCPT ); Tue, 3 Apr 2012 05:45:44 -0400 Message-ID: <4F7AC6A5.6050907@linux.vnet.ibm.com> Date: Tue, 03 Apr 2012 15:15:09 +0530 From: "Srivatsa S. Bhat" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120329 Thunderbird/11.0.1 MIME-Version: 1.0 To: Martin Steigerwald 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 Subject: Re: [REGRESSION] NMI received for unknown reason 3c on CPU 0, strange powersaving mode? References: <201203301304.49708.Martin@lichtvoll.de> <4F7987D0.3090106@linux.vnet.ibm.com> (sfid-20120402_143911_704229_5D7541F7) <201204030927.36606.Martin@lichtvoll.de> In-Reply-To: <201204030927.36606.Martin@lichtvoll.de> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8bit x-cbid: 12040309-4790-0000-0000-0000020E1B92 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/03/2012 12:57 PM, Martin Steigerwald wrote: > 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. Ok.. > >>> 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. > Yes, that's right. And moreover, the values in step 3 are in increasing order from freezer to core. Which means, the core level is a superset of everything before it. (So if you don't hit the problem with the core level, you won't hit it in any previous level.) Regards, Srivatsa S. Bhat