From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx143.postini.com [74.125.245.143]) by kanga.kvack.org (Postfix) with SMTP id CBB056B004D for ; Tue, 10 Apr 2012 06:40:54 -0400 (EDT) Date: Tue, 10 Apr 2012 11:40:50 +0100 From: Mel Gorman Subject: Re: [PATCH 2/2] mm: compaction: allow isolation of lower order buddy pages Message-ID: <20120410104050.GF3789@suse.de> References: <1333643534-1591-1-git-send-email-b.zolnierkie@samsung.com> <1333643534-1591-3-git-send-email-b.zolnierkie@samsung.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Disposition: inline In-Reply-To: <1333643534-1591-3-git-send-email-b.zolnierkie@samsung.com> Sender: owner-linux-mm@kvack.org List-ID: To: Bartlomiej Zolnierkiewicz Cc: linux-mm@kvack.org, Kyungmin Park On Thu, Apr 05, 2012 at 06:32:13PM +0200, Bartlomiej Zolnierkiewicz wrote: > Allow lower order buddy pages in suitable_migration_target() > so isolate_freepages() can isolate them as free pages during > compaction_alloc() phase. > > Cc: Mel Gorman > Signed-off-by: Bartlomiej Zolnierkiewicz > Signed-off-by: Kyungmin Park Nak. This patch depends on patch 1 to scan every page in isolate_freepages() and I explained why that is a problem already. That aside, a side-effect of this is that movable pages can get migrated to MIGRATE_UNMOVABLE and MIGRATE_RECLAIMABLE pageblocks. This will have a negative impact on fragmentation avoidance. In your particular use-case it will slightly increase allocation success rates early in the lifetime of the system at the cost of degrading success rates later. -- Mel Gorman SUSE Labs -- 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/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org