From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760346AbZBXUpn (ORCPT ); Tue, 24 Feb 2009 15:45:43 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759695AbZBXUp1 (ORCPT ); Tue, 24 Feb 2009 15:45:27 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:60663 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759481AbZBXUp0 (ORCPT ); Tue, 24 Feb 2009 15:45:26 -0500 Date: Tue, 24 Feb 2009 21:45:02 +0100 From: Ingo Molnar To: Mathieu Desnoyers Cc: "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List Subject: Re: [Bug #12660] Linux 2.6.28.3 freezing on a 32-bits x86 Thinkpad T43p Message-ID: <20090224204502.GC15161@elte.hu> References: <20090224072902.GA20098@elte.hu> <20090224161324.GB2803@Krystal> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090224161324.GB2803@Krystal> User-Agent: Mutt/1.5.18 (2008-05-17) 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 * Mathieu Desnoyers wrote: > * Ingo Molnar (mingo@elte.hu) wrote: > > > > * Rafael J. Wysocki wrote: > > > > > This message has been generated automatically as a part of a report > > > of recent regressions. > > > > > > The following bug entry is on the current list of known regressions > > > from 2.6.28. Please verify if it still should be listed and let me know > > > (either way). > > > > > > > > > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=12660 > > > Subject : Linux 2.6.28.3 freezing on a 32-bits x86 Thinkpad T43p > > > Submitter : Mathieu Desnoyers > > > Date : 2009-02-04 21:11 (20 days old) > > > References : http://marc.info/?l=linux-kernel&m=123378196022258&w=4 > > > Handled-By : Ingo Molnar > > > > Mathieu, this bug is very weird and makes little sense. Could > > you please reproduce it with vanilla -git too (without any LTT > > patches applied) and send the full boot+crash log? > > > > Ingo > > Hi Ingo, > > The last time I reproduced this bug (before going back to 2.6.27 on this > machine) was with a vanilla 2.6.28.5 kernel with the following patche > applied. So maybe this patch is actually causing the problem now that > other memory problems have been fixed since 2.6.28.3. I'll try without > it, but it can take a while before the bug reappears, we'll see. > > Mathieu > > > diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c > index 84ba748..fb12f06 100644 > --- a/arch/x86/mm/pageattr.c > +++ b/arch/x86/mm/pageattr.c > @@ -576,6 +576,13 @@ static int __change_page_attr(struct cpa_data *cpa, int primary) > else > address = *cpa->vaddr; > > + /* > + * If we're called with lazy mmu updates enabled, the > + * in-memory pte state may be stale. Flush pending updates to > + * bring them up to date. > + */ > + arch_flush_lazy_mmu_mode(); > + > repeat: > kpte = lookup_address(address, &level); > if (!kpte) > @@ -854,6 +861,13 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages, > } else > cpa_flush_all(cache); > > + /* > + * If we've been called with lazy mmu updates enabled, then > + * make sure that everything gets flushed out before we > + * return. > + */ > + arch_flush_lazy_mmu_mode(); > + > out: > return ret; > } there's a fix related to that commit: d85cf93: x86/paravirt: make arch_flush_lazy_mmu/cpu disable preemption Ingo