From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1762597Ab0HGHCc (ORCPT ); Sat, 7 Aug 2010 03:02:32 -0400 Received: from mx3.mail.elte.hu ([157.181.1.138]:60805 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752805Ab0HGHC1 (ORCPT ); Sat, 7 Aug 2010 03:02:27 -0400 Date: Sat, 7 Aug 2010 09:01:35 +0200 From: Ingo Molnar To: Frederic Weisbecker , Linus Torvalds Cc: Li Zefan , LKML , Peter Zijlstra , Thomas Gleixner Subject: Re: [PATCH] lockup_detector: Make DETECT_HUNT_TASK default depend on LOCKUP_DETECTOR Message-ID: <20100807070135.GC23108@elte.hu> References: <4C58C7FF.5060906@cn.fujitsu.com> <20100806005801.GB5436@nowhere> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20100806005801.GB5436@nowhere> User-Agent: Mutt/1.5.20 (2009-08-17) X-ELTE-SpamScore: -2.0 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-2.0 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.5 -2.0 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 (Linus Cc:-ed) * Frederic Weisbecker wrote: > On Wed, Aug 04, 2010 at 09:53:03AM +0800, Li Zefan wrote: > > CONFIG_DETECT_SOFTLOCKUP has been removed, so switch the > > default value to LOCKUP_DETECTOR. > > > > Also fix the help text of BOOT_PRINTK_DELAY. > > > > Signed-off-by: Li Zefan > > --- > > > Acked-by: Frederic Weisbecker > > Thanks. The thing is, CONFIG_DETECT_SOFTLOCKUP was default-y before, so many people had it enabled [and had it forced-enabled if DEBUG_KERNEL was off], even if they didnt really want or need it. So i turned off the new generic watchdog code's default intentionally - as it clearly does not cure cancer ;-) I think distros will enable it, and most testers will as well. Those who dont enable it and run into a lockup have an easy option to enable. Maybe a better change would be to make it more generally available - right now it's: config LOCKUP_DETECTOR bool "Detect Hard and Soft Lockups" depends on DEBUG_KERNEL && !S390 which means that it cannot be enabled when DEBUG_KERNEL is off. So i think we should: - Remove the s390 hack and add an ARCH_HAS_LOCKUP_DETECTOR flag - Remove the DEBUG_KERNEL dependency Hm? Thanks, Ingo