From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753915Ab2IFNAG (ORCPT ); Thu, 6 Sep 2012 09:00:06 -0400 Received: from mail-we0-f174.google.com ([74.125.82.174]:47321 "EHLO mail-we0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753331Ab2IFNAE (ORCPT ); Thu, 6 Sep 2012 09:00:04 -0400 From: Michal Nazarewicz To: Minchan Kim Cc: Kamezawa Hiroyuki , Yasuaki Ishimatsu , Andrew Morton , Bartlomiej Zolnierkiewicz , Mel Gorman , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mel Gorman , Konrad Rzeszutek Wilk Subject: Re: [RFC] memory-hotplug: remove MIGRATE_ISOLATE from free_area->free_list In-Reply-To: <20120906020850.GA31615@bbox> Organization: http://mina86.com/ References: <1346830033-32069-1-git-send-email-minchan@kernel.org> <20120906020850.GA31615@bbox> User-Agent: Notmuch/0.14+22~g8bdc16b (http://notmuchmail.org) Emacs/24.2.50.1 (x86_64-unknown-linux-gnu) X-Face: PbkBB1w#)bOqd`iCe"Ds{e+!C7`pkC9a|f)Qo^BMQvy\q5x3?vDQJeN(DS?|-^$uMti[3D*#^_Ts"pU$jBQLq~Ud6iNwAw_r_o_4]|JO?]}P_}Nc&"p#D(ZgUb4uCNPe7~a[DbPG0T~!&c.y$Ur,=N4RT>]dNpd;KFrfMCylc}gc??'U2j,!8%xdD Face: 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 X-PGP: 50751FF4 X-PGP-FP: AC1F 5F5C D418 88F8 CC84 5858 2060 4012 5075 1FF4 Date: Thu, 06 Sep 2012 14:59:53 +0200 Message-ID: MIME-Version: 1.0 Content-Type: multipart/mixed; boundary="=-=-=" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable > On Wed, Sep 05, 2012 at 07:28:23PM +0200, Michal Nazarewicz wrote: >> If you ask me, I'm not convinced that this improves anything. On Thu, Sep 06 2012, Minchan Kim wrote: > At least, it removes MIGRATE_ISOLATE type in free_area->free_list > which is very irony type as I mentioned. I really don't like such > type in free_area. What's the benefit if we remain code as it is? > It could make more problem in future. I don't really see current situation as making more problems in the future compared to this code. You are introducing a new state for a page (ie. it's not in buddy, but in some new limbo state) and add a bunch of new code and thus bunch of new bugs. I don't see how this improves things over having generic code that handles moving pages between free lists. PS. free_list does exactly what it says on the tin -> the pages are free, ie. unallocated. It does not say that they can be allocated. ;) --=20 Best regards, _ _ .o. | Liege of Serenely Enlightened Majesty of o' \,=3D./ `o ..o | Computer Science, Micha=C5=82 =E2=80=9Cmina86=E2=80=9D Nazarewicz = (o o) ooo +------------------ooO--(_)--Ooo-- --=-=-= Content-Type: multipart/signed; boundary="==-=-="; micalg=pgp-sha1; protocol="application/pgp-signature" --==-=-= Content-Type: text/plain --==-=-= Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.10 (GNU/Linux) iQIcBAEBAgAGBQJQSJ5JAAoJECBgQBJQdR/0dbsP/1dKXsqBtAKfu9S+jlmbio6O LlYrEC70r/wcKgsKhAqN8itfFLNrIKDxNhv/sz1aXuKrCTq8QkeQT6kZswgWb/Mp 8/E2L0Z6XXmSjqJnmiDwPmoGDGUCQivE2XIXVkVeafhcqg9Z0HnvWsvVflJu56S4 dmuFsaliqp9iEGQEA+HkYI8VnaXK3sHYhOcOiL2G/4yYVyIlJoH2Pp4AZopeQvKZ vpCspAutB+HjTSpE6tJg/4LqhmWK6OwCFjBDAuBLmRVnUCqv1hyIMxz7c2bOObdT 1V9NHoMp0Gorzdky1J2rSH29EpugDavrx8f0kOrqzD6BqZhIno86RVHgTWEgCy8e zbRfecvUoABz+T78M57FjedIghB9yK/CmtvWqGg9apRUuMk6J6znb1Rtbp1bRKmn tKHkCjpBAW9faLT1EerHLvCEQmnvskV13phu3gDqEf5BWiDmASDz9Vso5zT4N1c9 SKqBpX4XLDL/evEELXM9qMgIHWG7mRJz+AHHaYDFFVheiIiyr0oGwtCFKpJDGkHh Sf8hvc6ehGYuBCjyH79mkuznIPPDIaWR9yioEXEAq52GsVXt6Xxlgz+oIR8ZYUqC GffYet3kmnbtX0wX6Z871YWbpk9lQTbaqDVg8OHkSwBM5x8PMVBUeSWNlE177QLd f5UNFmstTAGmOYE4wqdT =n5Wc -----END PGP SIGNATURE----- --==-=-=-- --=-=-=--