From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754968Ab3AaNXo (ORCPT ); Thu, 31 Jan 2013 08:23:44 -0500 Received: from hydra.sisk.pl ([212.160.235.94]:36171 "EHLO hydra.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753471Ab3AaNXl (ORCPT ); Thu, 31 Jan 2013 08:23:41 -0500 From: "Rafael J. Wysocki" To: Borislav Petkov Cc: Jiri Slaby , Bjorn Helgaas , x86@kernel.org, lkml , Konstantin Khlebnikov Subject: Re: Uhhuh. NMI received for unknown reason 2c on CPU 0. Date: Thu, 31 Jan 2013 14:29:53 +0100 Message-ID: <8449445.ZpDikfZkfG@vostro.rjw.lan> User-Agent: KMail/4.9.5 (Linux/3.8.0-rc5; KDE/4.9.5; x86_64; ; ) In-Reply-To: <20130131131805.GG4926@pd.tnic> References: <20130129202848.GE25415@pd.tnic> <510A2B1C.1060108@suse.cz> <20130131131805.GG4926@pd.tnic> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="utf-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, January 31, 2013 02:18:05 PM Borislav Petkov wrote: > On Thu, Jan 31, 2013 at 09:28:12AM +0100, Jiri Slaby wrote: > > And, does it happen if you switch all of them but NMI wtd in there? > > No, but something else happens. Here's the whole dance: > > 1. Switch all tunables except "NMI watchdog should be turned off" to "Good" > 2. suspend to disk > 3. resume... all good > 4. switch "NMI watchdog should be turned off" to "Good" > 5. suspend to disk > 6. resume... all good > 7. start powertop, toggle "Wireless Power Saving for interface wlan0" twice. > I.e., "Good" -> "Bad"; "Bad" -> "Good". > > -> Boom! Unknown reason NMI. It happened right during the toggle because > it appeared in the framebuffer console (no X) right during me toggling > this. > > So, it is something getting fishy *after* the watchdog gets disabled. > Something remains funny and dangling, causing it to fire an NMI because > it is an NMI watchdog (doh!)... Could it be that the watchdog_disable > fact doesn't get communicated to the image kernel somehow, or maybe > delayed? The image kernel has no idea whether or not the watchdog has been disabled in the boot kernel. It needs to be disabled in both. > > > And if I pass nmi_watchdog=0 to the image kernel, it should be gone I > > guess. > > How do you pass options the image kernel? The image kernel has the same set of command line options that was used by that kernel before hibernation. Thanks, Rafael -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center.