From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756791AbXGMKVS (ORCPT ); Fri, 13 Jul 2007 06:21:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753222AbXGMKVD (ORCPT ); Fri, 13 Jul 2007 06:21:03 -0400 Received: from hellhawk.shadowen.org ([80.68.90.175]:1811 "EHLO hellhawk.shadowen.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752304AbXGMKVB (ORCPT ); Fri, 13 Jul 2007 06:21:01 -0400 Message-ID: <469751E9.7060904@shadowen.org> Date: Fri, 13 Jul 2007 11:20:25 +0100 From: Andy Whitcroft User-Agent: Icedove 1.5.0.9 (X11/20061220) MIME-Version: 1.0 To: Andrew Morton CC: Mel Gorman , npiggin@suse.de, kenchen@google.com, jschopp@austin.ibm.com, kamezawa.hiroyu@jp.fujitsu.com, a.p.zijlstra@chello.nl, y-goto@jp.fujitsu.com, clameter@sgi.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: -mm merge plans -- anti-fragmentation References: <20070710102043.GA20303@skynet.ie> <20070712122925.192a6601.akpm@linux-foundation.org> In-Reply-To: <20070712122925.192a6601.akpm@linux-foundation.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton wrote: > On Tue, 10 Jul 2007 11:20:43 +0100 > mel@skynet.ie (Mel Gorman) wrote: > >>> create-the-zone_movable-zone.patch >>> allow-huge-page-allocations-to-use-gfp_high_movable.patch >>> handle-kernelcore=-generic.patch >>> >>> Mel's moveable-zone work. In a similar situation. We need to stop whatever >>> we're doing and get down and work out what we're going to do with all this >>> stuff. >>> >> Whatever about grouping pages by mobility, I would like to see these go >> through. They have a real application for hugetlb pool resizing where the >> administrator knows the range of hugepages that will be required but doesn't >> want to waste memory when the required number of hugepages is small. I've >> cc'd Kenneth Chen as I believe he has run into this problem recently where >> I believe partitioning memory would have helped. He'll either confirm or deny. > > Still no decision here, really. > > Should we at least go for > > add-__gfp_movable-for-callers-to-flag-allocations-from-high-memory-that-may-be-migrated.patch > create-the-zone_movable-zone.patch > allow-huge-page-allocations-to-use-gfp_high_movable.patch > handle-kernelcore=-generic.patch > > in 2.6.23? These patches are pretty simple and self-contained utilising the existing zone infrastructure. They provide a significant degree of placement control when configured, which gives a lot of the benefits of grouping-pages-by-mobility. Merging these would seem like a low-risk option. Having a degree of placement control as delivered by ZONE_MOVABLE greatly increases the effectiveness of lumpy reclaim at higher orders. These patches plus lumpy would (IMO) provide a good base for further development. In particular I would envisage better usability for hugepage users in terms of simpler configuration. I would like to see ZONE_MOVABLE and lumpy considered for 2.6.23. -apw