From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754677Ab1HYQrF (ORCPT ); Thu, 25 Aug 2011 12:47:05 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:55305 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754669Ab1HYQrA (ORCPT ); Thu, 25 Aug 2011 12:47:00 -0400 Date: Thu, 25 Aug 2011 18:46:49 +0200 From: Tejun Heo To: Linus Torvalds Cc: Anders Eriksson , Suresh Siddha , Peter Anvin , Ingo Molnar , Sergei Shtylyov , linux-kernel@vger.kernel.org Subject: Re: mtrr failure, 3.1-rc1 Message-ID: <20110825164649.GL2803@mtj.dyndns.org> References: <20110825070335.3095B3BC183@tippex.mynet.homeunix.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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. 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; }