Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756845Ab0GFC07 (ORCPT ); Mon, 5 Jul 2010 22:26:59 -0400 Received: from mx1.redhat.com ([209.132.183.28]:56561 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754328Ab0GFC05 (ORCPT ); Mon, 5 Jul 2010 22:26:57 -0400 Message-ID: <4C329450.2010703@redhat.com> Date: Tue, 06 Jul 2010 10:26:24 +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: Ali Gholami Rudi CC: Ingo Molnar , Peter Zijlstra , x86@kernel.org, venki@google.com, tglx@linutronix.de, suresh.b.siddha@intel.com, mingo@redhat.com, linux-kernel@vger.kernel.org, hpa@zytor.com Subject: Re: [regression] commit 6a4f3b52 causes invalid memtype References: <20100507075128@tarekhel> <4C319D61.5090002@redhat.com> <20100507092842@tarekhel> <4C31A7A0.1020800@redhat.com> <4c31ac7b.J+CU0Yt+zKZ9ho1fjKvu6Z1v@tarekhel> <20100705104035.GA28190@elte.hu> <20100507113814@tarekhel> In-Reply-To: <20100507113814@tarekhel> 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: 1403 Lines: 41 On 07/05/2010 07:38 PM, Ali Gholami Rudi wrote: > Ingo Molnar wrote: >>>>>> commit 2463eb8b3093995e09a0d41b3d78ee0cf5fb4249 >>>>>> Author: Peter Zijlstra >>>>>> Date: Sat May 29 15:31:43 2010 +0200 >>>>>> >>>>>> rbtree: Undo augmented trees performance damage >>>>> >>>>> Where can I get it? I couldn't find it either in >>>>> Linus' or x86 repo tip. >>>> http://git.kernel.org/tip/2463eb8b3093995e09a0d41b3d78ee0cf5fb4249 >>> >>> It does fix it. >> >> Hm, interesting. That's a pure performance fix - so why does it fix a >> regression? >> >> Does Peter's augmented rbtrees improvements fix a bug too, as a side-effect? >> If yes then we need to accelerate that commit - right now it's aimed for >> v2.6.36. > > Since the bug appears after commit 6a4f3b52, it seems to be > related to the value of memtype->subtree_max_end. Peter's > patch seems to change the way memtype->subtree_max_end is > updated, which seems to fix the problem too. Actually, this exposed a bug in augmented rbtree (http://lkml.org/lkml/2010/6/21/459). With commit 6a4f3b52, the bug was easier to trigger :-) > > Thanks, > Ali > > -- 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/