From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail202.messagelabs.com (mail202.messagelabs.com [216.82.254.227]) by kanga.kvack.org (Postfix) with SMTP id A3AAA6B01EE for ; Wed, 31 Mar 2010 10:17:45 -0400 (EDT) Date: Wed, 31 Mar 2010 09:17:30 -0500 (CDT) From: Christoph Lameter Subject: Re: [RFC][PATCH] migrate_pages:skip migration between intersect nodes In-Reply-To: Message-ID: References: <1269874629-1736-1-git-send-email-lliubbo@gmail.com> <28c262361003291703i5382e342q773ffb16e3324cf5@mail.gmail.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org To: Bob Liu Cc: Minchan Kim , akpm@linux-foundation.org, linux-mm@kvack.org, lee.schermerhorn@hp.com, andi@firstfloor.org, kosaki.motohiro@jp.fujitsu.com List-ID: On Wed, 31 Mar 2010, Bob Liu wrote: > > The intended semantic is the preservation of the relative position of the > > page to the beginning of the node set. If you do not want to preserve the > > relative position then just move portions of the nodes around. > > > > Hmm., > Sorry I still haven't understand your mention :-) > > My concern was why move the pages in the intersect nodes.I think skipping > this migration we can also satisfy the user's request. > In the above semantic, I haven't got the result. No skipping does *not* satisfy the users request since the relative position of the page from the beginning of the nodesset is not preserved. You end up with a mess without this requirement. F.e. if you use page migration (or cpuset automigration) to shift an application running on 10 nodes up by two nodes to make a hole that would allow you to run another application on the lower nodes. Applications place pages intentionally on certain nodes to be able to manage memory distances. -- 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