From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757630AbZBKUOJ (ORCPT ); Wed, 11 Feb 2009 15:14:09 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755538AbZBKUNz (ORCPT ); Wed, 11 Feb 2009 15:13:55 -0500 Received: from tomts10.bellnexxia.net ([209.226.175.54]:49594 "EHLO tomts10-srv.bellnexxia.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750875AbZBKUNy (ORCPT ); Wed, 11 Feb 2009 15:13:54 -0500 X-Greylist: delayed 2537 seconds by postgrey-1.27 at vger.kernel.org; Wed, 11 Feb 2009 15:13:54 EST X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: ArwEAN+/kklMQWt2/2dsb2JhbACBbtNdhBsG Date: Wed, 11 Feb 2009 15:13:49 -0500 From: Mathieu Desnoyers To: Ingo Molnar Cc: Avi Kivity , Andrew Morton , Thomas Gleixner , Greg KH , ltt-dev@lists.casi.polymtl.ca, linux-kernel@vger.kernel.org, kvm@vger.kernel.org Subject: Re: [BUG] Linux 2.6.28.4 freezing on a 32-bits x86 Thinkpad T43p Message-ID: <20090211201349.GB32122@Krystal> References: <20090204211106.GA30824@Krystal> <20090204211759.GK22608@elte.hu> <20090211193125.GA30975@Krystal> <20090211195038.GC25968@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Content-Disposition: inline In-Reply-To: <20090211195038.GC25968@elte.hu> X-Editor: vi X-Info: http://krystal.dyndns.org:8080 X-Operating-System: Linux/2.6.21.3-grsec (i686) X-Uptime: 15:09:58 up 41 days, 20:08, 4 users, load average: 1.56, 0.55, 0.30 User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Ingo Molnar (mingo@elte.hu) wrote: > > * Mathieu Desnoyers wrote: > > > Here is a new backtrace, taken with a huge amount of debugging active, which still > > points to an interrupt handler nested over kvm_mmu_pte_write as the culprit. It's > > weird that the kvm code gets called on my modest Pentium M laptop, which I think > > has no VT-x support at all. I am not running any KVM VMs on this machine. The > > problem still happens on 2.6.28.4, and Slub redzones did not identify any memory > > corruption. This could be due to kvm_mmu_pte_write which either should not be > > called at all, or due to improper interrupt disabling in this function. > > Does latest tip:master fix it? In particular this one: > > 9cf161a: x86/cpa: make sure cpa is safe to call in lazy mmu mode > > fixes a crasher related to KVM and mmu notifiers ... > > Ingo I'll try to apply commit 9cf161a: x86/cpa: make sure cpa is safe to call in lazy mmu mode To my 2.6.28.4 kernel to change the configuration minimally and see if it helps. I guess we'll have to wait a few days before the problem is reproduced, and even more if it's not. :) Thanks a lot! Mathieu -- Mathieu Desnoyers OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68