From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757705AbXGJPvI (ORCPT ); Tue, 10 Jul 2007 11:51:08 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751757AbXGJPuz (ORCPT ); Tue, 10 Jul 2007 11:50:55 -0400 Received: from calculon.skynet.ie ([193.1.99.88]:57484 "EHLO calculon.skynet.ie" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751266AbXGJPuz (ORCPT ); Tue, 10 Jul 2007 11:50:55 -0400 Date: Tue, 10 Jul 2007 16:50:51 +0100 To: KAMEZAWA Hiroyuki Cc: Andrew Morton , npiggin@suse.de, kenchen@google.com, jschopp@austin.ibm.com, apw@shadowen.org, 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 Message-ID: <20070710155051.GA26249@skynet.ie> References: <20070710102043.GA20303@skynet.ie> <20070710200115.b5bbfb4a.kamezawa.hiroyu@jp.fujitsu.com> <20070710111202.GC25512@skynet.ie> <20070710203848.e7bbc98e.kamezawa.hiroyu@jp.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <20070710203848.e7bbc98e.kamezawa.hiroyu@jp.fujitsu.com> User-Agent: Mutt/1.5.13 (2006-08-11) From: mel@skynet.ie (Mel Gorman) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On (10/07/07 20:38), KAMEZAWA Hiroyuki didst pronounce: > On Tue, 10 Jul 2007 12:12:02 +0100 > mel@skynet.ie (Mel Gorman) wrote: > > > For (2), we need some method for specifing the range we will remove. For doing that, > > > ZONE seems to be good candidate. Now we use "kernelcore=" boot option to create > > > ZONE_MOVABLE by hand. > > > > At the risk of putting you on the spot, do you mind saying whether the > > grouping pages by mobility and ZONE_MOVABLE patches are going in the > > direction you want or should something totally different be done? If > > they are going the right direction, is there anything critical that is > > missing right now? > > > "grouping pages by mobility and ZONE_MOVABLE" things are what I want. And > I want to go with them. But I know some people doesn't want to increase # > of zones. It is my concern. I'm not overly keen on increasing the number of zones either but it is a simplier approach, solves some of the problems and is less intrusive than grouping pages by mobility so it's a reasonable starting point. > I know ZONE_MOVABLE works well but there are people who don't want new zone. > So making ZONE_MOVABLE as configurable will be good thing, as Nick Piggin pointed. > I tested your zone-configurable patch and they appear to work. Your patch builds whether ZONE_MOVABLE is available or not and ZONE_MOVABLE is only available when the config option is set. It is also considerably cleaner than the patch I put together for a configurable ZONE_MOVABLE which is too ugly to live in comparison. > About my other concerns , see node hotplug (below). > > > > But this is the first step. I know Intel guy posted > > > his idea to specify Hotpluggable-Memory range in SRAT (by firmware). > > > > There may be additional work required to make this play nicely with > > ZONE_MOVABLE but it shouldn't be anything fundamental. > > > yes. And I don't know his idea about SRAT is acceped in firmware comunity or not. > For now, kernelcore= works enough for memory hotplug. > Sounds good. > > > And I think that > > > other method may be introduced for node-hotplug. > > > > > > > Same as above really. If the node contains one zone - ZONE_MOVABLE, it > > would work for unplugging. > > > Our concern on node hotplug is "bootmem" and hashtable , pgdata, memmap etc.... > NUMA initilization (of each arch) includes something complicated. > But this is not directly related to ZONE_MOVABLE things I think. > It's node-hotplug problem. > We are now consdiering hot-add nodes after initcalls(). > I don't see off-hand how it's so different from normal memory hot-add but I'll take your word for it. I'll keep an eye out for patches related to it. Thanks -- Mel Gorman Part-time Phd Student Linux Technology Center University of Limerick IBM Dublin Software Lab