From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754763Ab2KGKtr (ORCPT ); Wed, 7 Nov 2012 05:49:47 -0500 Received: from cantor2.suse.de ([195.135.220.15]:59069 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754274Ab2KGKtp (ORCPT ); Wed, 7 Nov 2012 05:49:45 -0500 Date: Wed, 7 Nov 2012 10:49:40 +0000 From: Mel Gorman To: Rik van Riel Cc: Peter Zijlstra , Andrea Arcangeli , Ingo Molnar , Johannes Weiner , Hugh Dickins , Thomas Gleixner , Linus Torvalds , Andrew Morton , Linux-MM , LKML Subject: Re: [PATCH 15/19] mm: numa: Add fault driven placement and migration Message-ID: <20121107104940.GU8218@suse.de> References: <1352193295-26815-1-git-send-email-mgorman@suse.de> <1352193295-26815-16-git-send-email-mgorman@suse.de> <509967D9.7050706@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <509967D9.7050706@redhat.com> 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 On Tue, Nov 06, 2012 at 02:41:13PM -0500, Rik van Riel wrote: > On 11/06/2012 04:14 AM, Mel Gorman wrote: > >From: Peter Zijlstra > > > >NOTE: This patch is based on "sched, numa, mm: Add fault driven > > placement and migration policy" but as it throws away all the policy > > to just leave a basic foundation I had to drop the signed-offs-by. > > > >This patch creates a bare-bones method for setting PTEs pte_numa in the > >context of the scheduler that when faulted later will be faulted onto the > >node the CPU is running on. In itself this does nothing useful but any > >placement policy will fundamentally depend on receiving hints on placement > >from fault context and doing something intelligent about it. > > > >Signed-off-by: Mel Gorman > > Excellent basis for implementing a smarter NUMA > policy. > > Not sure if such a policy should be implemented > as a replacement for this patch, or on top of it... > I'm expecting on top of it. As a POC, I'm looking at implementing the CPU Follows Memory algorithm (mostly from autonuma) on top of this but using the home-node logic from schednuma to handle how processes get scheduled. MORON will need to relax to take the home node into account to avoid fighting the home-node decisions. task_numa_fault() determines if the home node needs to change based on statistics it gathers from faults. So far I am keeping within the framework but it is still a WIP. > Either way, thank you for cleaning up all of the > NUMA base code, while I was away at conferences > and stuck in airports :) > My pleasure. Thanks a lot for reviewing this! -- Mel Gorman SUSE Labs