From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932845Ab2HHSpe (ORCPT ); Wed, 8 Aug 2012 14:45:34 -0400 Received: from mx1.redhat.com ([209.132.183.28]:43548 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964822Ab2HHSpd (ORCPT ); Wed, 8 Aug 2012 14:45:33 -0400 Message-ID: <5022B356.9060902@redhat.com> Date: Wed, 08 Aug 2012 14:43:34 -0400 From: Rik van Riel User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120605 Thunderbird/13.0 MIME-Version: 1.0 To: Andrea Arcangeli CC: Peter Zijlstra , mingo@kernel.org, oleg@redhat.com, pjt@google.com, akpm@linux-foundation.org, torvalds@linux-foundation.org, tglx@linutronix.de, Lee.Schermerhorn@hp.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 00/19] sched-numa rewrite References: <20120731191204.540691987@chello.nl> <20120808171714.GM10459@redhat.com> In-Reply-To: <20120808171714.GM10459@redhat.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 On 08/08/2012 01:17 PM, Andrea Arcangeli wrote: > Hi everyone, > > On Tue, Jul 31, 2012 at 09:12:04PM +0200, Peter Zijlstra wrote: >> Hi all, >> >> After having had a talk with Rik about all this NUMA nonsense where he proposed >> the scheme implemented in the next to last patch, I came up with a related >> means of doing the home-node selection. >> >> I've also switched to (ab)using PROT_NONE for driving the migration faults. > > I'm glad we agree on the introduction of the numa hinting page faults. > > I run a benchmark to compare your sched-numa rewrite with autonuma22: > > http://www.kernel.org/pub/linux/kernel/people/andrea/autonuma/autonuma-vs-sched-numa-rewrite-20120808.pdf For the people who have not yet read that PDF: While the sched-numa code is relatively small and clean, the current version does not seem to offer a significant performance improvement over not having it, and in one of the tests performance actually regresses vs. mainline. On the other hand, the autonuma code is pretty large and hard to understand, but it does provide a significant speedup on each of the tests. I have not looked at why sched-numa is not giving a significant performance improvement.