From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757425AbYDWNhZ (ORCPT ); Wed, 23 Apr 2008 09:37:25 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753307AbYDWNhN (ORCPT ); Wed, 23 Apr 2008 09:37:13 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:56681 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752533AbYDWNhL (ORCPT ); Wed, 23 Apr 2008 09:37:11 -0400 Date: Wed, 23 Apr 2008 15:36:56 +0200 From: Ingo Molnar To: David Miller Cc: linux-kernel@vger.kernel.org, tglx@linutronix.de, a.p.zijlstra@chello.nl Subject: Re: [patch] softlockup: fix false positives on nohz if CPU is 100% idle for more than 60 seconds Message-ID: <20080423133656.GA23782@elte.hu> References: <20080422.030519.259068348.davem@davemloft.net> <20080423085030.GA22309@elte.hu> <20080423.035544.110883549.davem@davemloft.net> <20080423.052928.142823681.davem@davemloft.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080423.052928.142823681.davem@davemloft.net> User-Agent: Mutt/1.5.17 (2007-11-01) 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 * David Miller wrote: > > It may take some time, as each test run the verify the existence of > > the problem takes several minutes. > > Ok, Ingo, none of your patches fix even the initial buggy changeset, > for reference: as a temporary workaround please try the patch below, until we can reproduce and fix the bug. Ingo -------------------------------> Subject: softlockup: nohz workaround From: Ingo Molnar Date: Wed Apr 23 15:19:32 CEST 2008 Signed-off-by: Ingo Molnar --- kernel/softlockup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) Index: linux/kernel/softlockup.c =================================================================== --- linux.orig/kernel/softlockup.c +++ linux/kernel/softlockup.c @@ -245,7 +245,7 @@ static int watchdog(void *__bind_cpu) */ while (!kthread_should_stop()) { touch_softlockup_watchdog(); - schedule(); + schedule_timeout(softlockup_thresh/2); if (kthread_should_stop()) break;