Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755088AbYGRHRr (ORCPT ); Fri, 18 Jul 2008 03:17:47 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753251AbYGRHRj (ORCPT ); Fri, 18 Jul 2008 03:17:39 -0400 Received: from mail.crca.org.au ([67.207.131.56]:50591 "EHLO crca.org.au" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753095AbYGRHRi (ORCPT ); Fri, 18 Jul 2008 03:17:38 -0400 X-Bogosity: Ham, spamicity=0.000000 Subject: Re: [Bug #11035] System hangs on 2.6.26-rc8 From: Nigel Cunningham To: Ingo Molnar Cc: Roman Mindalev , "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Thomas Gleixner , Vegard Nossum In-Reply-To: <20080718071121.GB6875@elte.hu> References: <4878D259.7050403@r000n.net> <487CA8E5.8020208@r000n.net> <20080718071121.GB6875@elte.hu> Content-Type: text/plain Organization: Christian Reformed Churches of Australia Date: Fri, 18 Jul 2008 17:17:32 +1000 Message-Id: <1216365452.26544.22.camel@nigel-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.22.3.1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1869 Lines: 51 Hi. On Fri, 2008-07-18 at 09:11 +0200, Ingo Molnar wrote: > * Roman Mindalev wrote: > > > I done bisection. > > Result below: > > > > 8f46924600e30b140445f5b84abe9b80d2fff5fb is first bad commit > > commit 8f46924600e30b140445f5b84abe9b80d2fff5fb > > Author: Ingo Molnar > > Date: Wed Jan 30 13:34:09 2008 +0100 > > > > x86: enable CONFIG_DEBUG_PAGEALLOC more widely > > > > make CONFIG_DEBUG_PAGEALLOC universally available. > > > > CONFIG_HIBERNATION and CONFIG_HUGETLBFS was disabling it, for no > > particular reason. > > as far as i can see you see a lockup under certain circumstances, right? > > this debug option catches use-after-free and other types of invalid > memory accesses. When it catches a bug the kernel most likely crashes > and produces a backlog. Because you are in graphical mode that is not > visible. > > This would possibly be debuggable if you set up netconsole logging to > another system on a local LAN - see > Documentation/networking/netconsole.txt. > > Vegard - would it be possible to make DEBUG_PAGEALLOC faults single-shot > and non-fatal, just like kmemcheck does it? That way people would see a > nice kernel message instead of an immediate crash. That means we'd have > to find a reliable filter for DEBUG_PAGEALLOC-provoked pagefaults though > ... Not that it matters now, but that original commit message was wrong - CONFIG_HIBERNATION used to be incompatible with CONFIG_DEBUG_PAGEALLOC because [u]swsusp didn't (until very recently) handle the fact that DEBUG_SLAB unmaps empty pages on x86. Regards, Nigel -- 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/