From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1765180AbXLUAGV (ORCPT ); Thu, 20 Dec 2007 19:06:21 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759647AbXLUAGE (ORCPT ); Thu, 20 Dec 2007 19:06:04 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:51174 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754698AbXLUAGB (ORCPT ); Thu, 20 Dec 2007 19:06:01 -0500 Date: Fri, 21 Dec 2007 01:05:34 +0100 From: Ingo Molnar To: Andrew Morton Cc: trond.myklebust@fys.uio.no, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org Subject: Re: Linux 2.6.24-rc5 x86 architecture no longer Oopses... Message-ID: <20071221000534.GA5128@elte.hu> References: <1198190447.29917.9.camel@heimdal.trondhjem.org> <20071220145415.f737e7f3.akpm@linux-foundation.org> <20071220234759.GA29776@elte.hu> <20071220160203.f940f088.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071220160203.f940f088.akpm@linux-foundation.org> 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 * Andrew Morton wrote: > On Fri, 21 Dec 2007 00:47:59 +0100 > Ingo Molnar wrote: > > > it needs to be found out why the preempt_count suddenly went to zero. Is > > task struct corruption out of question? > > Strictly we shouldn't care - we _know_ we've already hit a kernel bug > and who knows, perhaps that buggy code did an unbalanced > preempt_disable(). So make the oops code more robust. > > otoh, we don't want to be hiding a bug. What piece of code guarantees > that we ender the oops code with preemption disabled? i looked at the patch you sent - and there the proof was in the sections i quoted. Ingo