From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753348AbaCMOiF (ORCPT ); Thu, 13 Mar 2014 10:38:05 -0400 Received: from mailout1.samsung.com ([203.254.224.24]:11645 "EHLO mailout1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751260AbaCMOiE (ORCPT ); Thu, 13 Mar 2014 10:38:04 -0400 X-AuditID: cbfee61a-b7fb26d00000724f-2b-5321c2c8e069 From: Bartlomiej Zolnierkiewicz To: Mel Gorman Cc: Hugh Dickins , Marek Szyprowski , Yong-Taek Lee , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [RFC][PATCH v2] mm/page_alloc: fix freeing of MIGRATE_RESERVE migratetype pages Date: Thu, 13 Mar 2014 15:37:46 +0100 Message-id: <3661570.lSOEkVGv4G@amdc1032> User-Agent: KMail/4.8.4 (Linux/3.2.0-54-generic-pae; KDE/4.8.5; i686; ; ) In-reply-to: <20140313142540.GQ10663@suse.de> References: <42197912.c6v2hLDCey@amdc1032> <20140313142540.GQ10663@suse.de> MIME-version: 1.0 Content-transfer-encoding: 7Bit Content-type: text/plain; charset=iso-8859-15 X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFrrILMWRmVeSWpSXmKPExsVy+t9jQd2ThxSDDTr/sVo8/dTHYnF51xw2 i3tr/rNarD1yl91i8rtnjBaP13M7sHks2FTqsenTJHaPvi2rGD02n672+LxJLoA1issmJTUn syy1SN8ugSvj6vseloJ+voonyzawNDCe5e5i5OCQEDCR2L+nrouRE8gUk7hwbz1bFyMXh5DA dEaJu/2rWCGcFiaJI5efsYBUsQlYSUxsX8UI0iwioCAx9705SA2zwFpGibOdD9lBaoQF4iSe /9nMBmKzCKhK3Px1DizOK6ApcXdTK1hcVMBTYsf2lWA2p4CuxKd/W8BqhAS8JT6tOMQGUS8o 8WPyPbC9zALyEvv2T2UF2csMVL9gg8cERoFZSKpmIamahVC1gJF5FaNoakFyQXFSeq6hXnFi bnFpXrpecn7uJkZwQD+T2sG4ssHiEKMAB6MSD++K5QrBQqyJZcWVuYcYJTiYlUR4rTcpBgvx piRWVqUW5ccXleakFh9ilOZgURLnPdBqHSgkkJ5YkpqdmlqQWgSTZeLglGpg3OdrXiZpyXju 4Z6o9CqlM9YHnjWde931ccOxqSvO97p/4py2f8mH1R9Neuy49J+lBZ1R4zB+VK3mtIftQ2TV l/Pmun0fvL+1xMYtnF78Y6vbp18sn/h5ftqVZR80vJPO12d5oeuR9YzFAfcnZatOO3lyc8ar p8eNJGwkb9ivYf3nlj93zT21b0osxRmJhlrMRcWJAAU59XtkAgAA Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thursday, March 13, 2014 02:25:40 PM Mel Gorman wrote: > On Fri, Feb 14, 2014 at 07:34:17PM +0100, Bartlomiej Zolnierkiewicz wrote: > > Pages allocated from MIGRATE_RESERVE migratetype pageblocks > > are not freed back to MIGRATE_RESERVE migratetype free > > lists in free_pcppages_bulk()->__free_one_page() if we got > > to free_pcppages_bulk() through drain_[zone_]pages(). > > The freeing through free_hot_cold_page() is okay because > > freepage migratetype is set to pageblock migratetype before > > calling free_pcppages_bulk(). If pages of MIGRATE_RESERVE > > migratetype end up on the free lists of other migratetype > > whole Reserved pageblock may be later changed to the other > > migratetype in __rmqueue_fallback() and it will be never > > changed back to be a Reserved pageblock. Fix the issue by > > preserving freepage migratetype as a pageblock migratetype > > (instead of overriding it to the requested migratetype) > > for MIGRATE_RESERVE migratetype pages in rmqueue_bulk(). > > > > The problem was introduced in v2.6.31 by commit ed0ae21 > > ("page allocator: do not call get_pageblock_migratetype() > > more than necessary"). > > > > Signed-off-by: Bartlomiej Zolnierkiewicz > > Reported-by: Yong-Taek Lee > > Cc: Marek Szyprowski > > Cc: Mel Gorman > > Cc: Hugh Dickins > > It's a pity about the unconditional pageblock lookup in that path but I > didn't see a better way around it so > > Acked-by: Mel Gorman Thanks but does that mean that v3 should be abandoned: https://lkml.org/lkml/2014/3/6/365 ? Best regards, -- Bartlomiej Zolnierkiewicz Samsung R&D Institute Poland Samsung Electronics