From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754971Ab1HYRjy (ORCPT ); Thu, 25 Aug 2011 13:39:54 -0400 Received: from mga14.intel.com ([143.182.124.37]:60828 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753349Ab1HYRjx (ORCPT ); Thu, 25 Aug 2011 13:39:53 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.68,281,1312182000"; d="scan'208";a="42428653" Subject: Re: mtrr failure, 3.1-rc1 From: Suresh Siddha Reply-To: Suresh Siddha To: Tejun Heo Cc: Linus Torvalds , Anders Eriksson , Peter Anvin , Ingo Molnar , Sergei Shtylyov , "linux-kernel@vger.kernel.org" Date: Thu, 25 Aug 2011 10:43:01 -0700 In-Reply-To: <20110825164649.GL2803@mtj.dyndns.org> References: <20110825070335.3095B3BC183@tippex.mynet.homeunix.org> <20110825164649.GL2803@mtj.dyndns.org> Organization: Intel Corp Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.0.1 (3.0.1-1.fc15) Content-Transfer-Encoding: 7bit Message-ID: <1314294182.16133.19.camel@sbsiddha-desk.sc.intel.com> Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 2011-08-25 at 09:46 -0700, Tejun Heo wrote: > Hello, > > On Thu, Aug 25, 2011 at 08:55:12AM -0700, Linus Torvalds wrote: > > Hmm. Some of those commits are marked for stable too. > > > > I'm adding appropriate parties to the discussion (authors and > > sign-offs from the five commits that that merge brings in), but it > > would also be great if you could bisect exactly which commit broke for > > you. You can make it quick by just doing > > > > git bisect start > > git bisect bad dc43d9fa73d82083656fb9c02f4823bcdcfb9f91 > > git bisect good dc43d9fa73d82083656fb9c02f4823bcdcfb9f91^ > > > > and it should take just a couple of tests. I *assume* it's the > > stop_machine changes by Tejun &co, but who knows.. > > > > Anders, is this a single-CPU system? > > Indeed, while removing custom rendezvous code and switching to > stop_machine, commit 192d8857427d "x86, mtrr: use stop_machine APIs > for doing MTRR rendezvous" completely dropped mtrr setting code on > !CONFIG_SMP. oops. My bad. Linus, Bad commit is not marked for stable. I was able to reproduce the issue and tested the below patch. It looks good. Thanks. Acked-by: Suresh Siddha > > Anders, if your kernel didn't have SMP turned on, can you please > verify the following patch fixes the problem? > > Thanks. > > diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c > index 08119a3..6b96110 100644 > --- a/arch/x86/kernel/cpu/mtrr/main.c > +++ b/arch/x86/kernel/cpu/mtrr/main.c > @@ -149,7 +149,6 @@ struct set_mtrr_data { > */ > static int mtrr_rendezvous_handler(void *info) > { > -#ifdef CONFIG_SMP > struct set_mtrr_data *data = info; > > /* > @@ -171,7 +170,6 @@ static int mtrr_rendezvous_handler(void *info) > } else if (mtrr_aps_delayed_init || !cpu_online(smp_processor_id())) { > mtrr_if->set_all(); > } > -#endif > return 0; > } >