From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from westrelay02.boulder.ibm.com (westrelay02.boulder.ibm.com [9.17.195.11]) by e33.co.us.ibm.com (8.12.11/8.12.11) with ESMTP id j9L3WShf029610 for ; Thu, 20 Oct 2005 23:32:28 -0400 Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by westrelay02.boulder.ibm.com (8.12.10/NCO/VERS6.7) with ESMTP id j9L3WSl8547694 for ; Thu, 20 Oct 2005 21:32:28 -0600 Received: from d03av01.boulder.ibm.com (loopback [127.0.0.1]) by d03av01.boulder.ibm.com (8.12.11/8.13.3) with ESMTP id j9L3WSR0010261 for ; Thu, 20 Oct 2005 21:32:28 -0600 Date: Thu, 20 Oct 2005 20:32:23 -0700 From: mike kravetz Subject: Re: [PATCH 0/4] Swap migration V3: Overview Message-ID: <20051021033223.GC6846@w-mikek2.ibm.com> References: <20051020225935.19761.57434.sendpatchset@schroedinger.engr.sgi.com> <20051020160638.58b4d08d.akpm@osdl.org> <20051020234621.GL5490@w-mikek2.ibm.com> <43585EDE.3090704@jp.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <43585EDE.3090704@jp.fujitsu.com> Sender: owner-linux-mm@kvack.org Return-Path: To: KAMEZAWA Hiroyuki Cc: Andrew Morton , Christoph Lameter , linux-kernel@vger.kernel.org, linux-mm@kvack.org, magnus.damm@gmail.com, marcelo.tosatti@cyclades.com List-ID: On Fri, Oct 21, 2005 at 12:22:06PM +0900, KAMEZAWA Hiroyuki wrote: > mike kravetz wrote: > >On Thu, Oct 20, 2005 at 04:06:38PM -0700, Andrew Morton wrote: > > >Just to be clear, there are at least two distinct requirements for hotplug. > >One only wants to remove a quantity of memory (location unimportant). The > >other wants to remove a specific section of memory (location specific). I > >think the first is easier to address. > > > > The only difficulty to remove a quantity of memory is how to find > where is easy to be removed. If this is fixed, I think it is > easier to address. We have been using Mel's fragmentation patches. One of the data structures created by these patches is a 'usemap' thats tracks how 'blocks' of memory are used. I exposed the usemaps via sysfs along with other hotplug memory section attributes. So, you can then have a user space program scan the usemaps looking for sections that can be easily offlined. -- Mike -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org