Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759300AbZANKs5 (ORCPT ); Wed, 14 Jan 2009 05:48:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754183AbZANKsi (ORCPT ); Wed, 14 Jan 2009 05:48:38 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:40501 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758557AbZANKsh (ORCPT ); Wed, 14 Jan 2009 05:48:37 -0500 Date: Wed, 14 Jan 2009 11:48:26 +0100 From: Ingo Molnar To: Mandeep Singh Baines Cc: linux-kernel@vger.kernel.org, rientjes@google.com, mbligh@google.com, thockin@google.com Subject: Re: [PATCH] softlock: fix false panic which can occur if softlockup_thresh is reduced Message-ID: <20090114104826.GF2913@elte.hu> References: <20090113051517.GA27227@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090113051517.GA27227@google.com> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 900 Lines: 26 * Mandeep Singh Baines wrote: > At run-time, if softlockup_thresh is changed to a much lower value, > touch_timestamp is likely to be much older than the new softlock_thresh. > > This will cause a false softlockup to be detected. If softlockup_panic > is enabled, the system will panic. > > The fix is to touch all watchdogs before changing softlockup_thresh. > > Signed-off-by: Mandeep Singh Baines > --- > include/linux/sched.h | 3 +++ > kernel/softlockup.c | 9 +++++++++ > kernel/sysctl.c | 2 +- > 3 files changed, 13 insertions(+), 1 deletions(-) applied to tip/core/urgent, thanks! Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/