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 5FDA16B01EE for ; Wed, 31 Mar 2010 00:02:32 -0400 (EDT) Received: by ywh13 with SMTP id 13so1362489ywh.12 for ; Tue, 30 Mar 2010 21:02:30 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: <1269874629-1736-1-git-send-email-lliubbo@gmail.com> <28c262361003291703i5382e342q773ffb16e3324cf5@mail.gmail.com> Date: Wed, 31 Mar 2010 12:02:27 +0800 Message-ID: Subject: Re: [RFC][PATCH] migrate_pages:skip migration between intersect nodes From: Bob Liu Content-Type: text/plain; charset=UTF-8 Sender: owner-linux-mm@kvack.org To: Minchan Kim Cc: Christoph Lameter , akpm@linux-foundation.org, linux-mm@kvack.org, lee.schermerhorn@hp.com, andi@firstfloor.org, kosaki.motohiro@jp.fujitsu.com List-ID: On 3/31/10, Minchan Kim wrote: > On Wed, Mar 31, 2010 at 10:36 AM, Bob Liu wrote: >> On 3/31/10, Christoph Lameter wrote: >>> On Tue, 30 Mar 2010, Minchan Kim wrote: >>> >>>> Hi, Bob >>>> >>>> On Mon, Mar 29, 2010 at 11:57 PM, Bob Liu wrote: >>>> > In current do_migrate_pages(),if from_nodes and to_nodes have some >>>> > intersect nodes,pages in these intersect nodes will also be >>>> > migrated. >>>> > eg. Assume that, from_nodes: 1,2,3,4 to_nodes: 2,3,4,5. Then these >>>> > migrates will happen: >>>> > migrate_pages(4,5); >>>> > migrate_pages(3,4); >>>> > migrate_pages(2,3); >>>> > migrate_pages(1,2); >>>> > >>>> > But the user just want all pages in from_nodes move to to_nodes, >>>> > only migrate(1,2)(ignore the intersect nodes.) can satisfied >>>> > the user's request. >>>> > >>>> > I amn't sure what's migrate_page's semantic. >>>> > Hoping for your suggestions. >>>> >>>> I didn't see 8:migratepages Lee pointed at that time. >>>> The description matches current migrate_pages's behavior exactly. >>>> >>>> I agree Lee's opinion. >>>> Let's wait Christoph's reply what is semantic >>>> and why it doesn't have man page. >>> >>> Manpage is part of numatools. >>> >>> 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. >> > > man page said. > > "For example if we move from nodes 2-5 to 7,9,12-13 then the preferred mode > of > operation is to move pages from 2->7, 3->9, 4->12 and 5->13. However, this > is only posssible if enough memory is available." > > If user uses migratepages((1,2,3,4), (2,3,4,5)), He want to move pages > (1->2), (2-3), (3->4), (4-5). It matches with magpage. > > But with your suggestion, only (1-2). > I think It doesn't match with man page. > Ok. I got it.. I used to didn't find numatools. Thanks all! > Do you want to add some words to make manpage more clear? > >> Thanks! >> -- >> Regards, >> -Bob >> > > > > -- > Kind regards, > Minchan Kim > -- Regards, --Bob -- 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