From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pb0-f46.google.com (mail-pb0-f46.google.com [209.85.160.46]) by kanga.kvack.org (Postfix) with ESMTP id 0F0C56B0035 for ; Thu, 13 Mar 2014 10:38:05 -0400 (EDT) Received: by mail-pb0-f46.google.com with SMTP id rq2so1192339pbb.33 for ; Thu, 13 Mar 2014 07:38:05 -0700 (PDT) Received: from mailout1.samsung.com (mailout1.samsung.com. [203.254.224.24]) by mx.google.com with ESMTPS id po10si1567376pab.425.2014.03.13.07.38.03 for (version=TLSv1 cipher=RC4-MD5 bits=128/128); Thu, 13 Mar 2014 07:38:05 -0700 (PDT) Received: from epcpsbgm1.samsung.com (epcpsbgm1 [203.254.230.26]) by mailout1.samsung.com (Oracle Communications Messaging Server 7u4-24.01(7.0.4.24.0) 64bit (built Nov 17 2011)) with ESMTP id <0N2D00BQCPZDXN10@mailout1.samsung.com> for linux-mm@kvack.org; Thu, 13 Mar 2014 23:38:01 +0900 (KST) From: Bartlomiej Zolnierkiewicz 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> 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 Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Hugh Dickins , Marek Szyprowski , Yong-Taek Lee , linux-mm@kvack.org, 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 -- 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