Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932230Ab0FVCqH (ORCPT ); Mon, 21 Jun 2010 22:46:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:19924 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758881Ab0FVCqD (ORCPT ); Mon, 21 Jun 2010 22:46:03 -0400 Message-ID: <4C2023D0.7010309@redhat.com> Date: Tue, 22 Jun 2010 10:45:36 +0800 From: Xiaotian Feng User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.9) Gecko/20100430 Fedora/3.0.4-2.fc12 Lightning/1.0b2pre Thunderbird/3.0.4 MIME-Version: 1.0 To: Suresh Siddha CC: Peter Zijlstra , Marcin Slusarz , Dan Carpenter , Thomas Gleixner , Ingo Molnar , "H.PeterA" , Venkatesh Pallipadi , Jack Steiner , "linux-kernel@vger.kernel.org" , "x86@kernel.org" Subject: Re: [patch] x86, pat: freeing invalid memtype messages References: <20100617134559.GA29824@bicker> <20100617161728.GA2741@joi.lan> <4C1B1691.6020809@redhat.com> <20100618175726.GA2785@joi.lan> <4C1F455E.6050502@redhat.com> <1277118155.1875.508.camel@laptop> <4C1F47EF.2060509@redhat.com> <20100621153303.GA2754@joi.lan> <1277134873.1875.520.camel@laptop> <1277142860.3017.22.camel@sbs-t61.sc.intel.com> In-Reply-To: <1277142860.3017.22.camel@sbs-t61.sc.intel.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2303 Lines: 57 On 06/22/2010 01:54 AM, Suresh Siddha wrote: > On Mon, 2010-06-21 at 08:41 -0700, Peter Zijlstra wrote: >> On Mon, 2010-06-21 at 17:33 +0200, Marcin Slusarz wrote: >>> On Mon, Jun 21, 2010 at 07:07:27PM +0800, Xiaotian Feng wrote: >>>> On 06/21/2010 07:02 PM, Peter Zijlstra wrote: >>>>> On Mon, 2010-06-21 at 18:56 +0800, Xiaotian Feng wrote: >>>>> >>>>>> I guess there might be something wrong between the augmented rbtree insert/remove .. >>>>> >>>>> The easiest thing is to revert that change and try again, the next step >>>>> would be to print the full RB tree on each modification and look where >>>>> it goes wrong. >>>>> >>>>> That said, I did print my fair share of (augmented) RB trees while >>>>> playing with scheduler patches and I can't remember it ever having >>>>> messed up like that. >>>> He's using 2.6.35-rc2+, without your "rbtree: Undo augmented trees >>>> performance damage" patch ;-) >>> >>> I applied it manually (commit 2463eb8b3093995e09a0d41b3d78ee0cf5fb4249 from -tip) >>> to 2.6.35-rc3 and it fixed both acpi's and nouveau's "invalid memtype" messages. >>> Thanks. >> >> Oh neat, so it actually fixes a bug in the previous augmented rb-tree >> implementation? > > When I was reviewing your fix, it looked like that prior to your fix we > were re-augmenting only at points where we do the tree rotations/color > change and at the points of node insertion/removal. I don't think we > were re-augmenting all the parent nodes in the path of the selected-node > that is going to replace the deleted node. > > Perhaps we were hitting this issue here. Were it from a insert without any rotations/color changes? This case is performing insert A/remove A/ 2nd insert A/ 2nd remove A/3rd insert A. And the 2nd remove shows us the invalid memtype. 3rd insert shows us it is in the rbtree. All I can image is that get_subtree_max_end in memtype_rb_lowest_match returned stale value. It looks like we don't re-augment the parent nodes if there aren't any rotations/color changes in the rb_insert_color(). > > thanks, > suresh > > -- 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/