From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f174.google.com (mail-pd0-f174.google.com [209.85.192.174]) by kanga.kvack.org (Postfix) with ESMTP id F06BB6B0035 for ; Fri, 14 Feb 2014 01:54:08 -0500 (EST) Received: by mail-pd0-f174.google.com with SMTP id z10so11639875pdj.33 for ; Thu, 13 Feb 2014 22:54:08 -0800 (PST) Received: from LGEAMRELO02.lge.com (lgeamrelo02.lge.com. [156.147.1.126]) by mx.google.com with ESMTP id xk2si4652379pab.71.2014.02.13.22.54.06 for ; Thu, 13 Feb 2014 22:54:07 -0800 (PST) From: Joonsoo Kim Subject: [PATCH v2 2/5] mm/compaction: do not call suitable_migration_target() on every page Date: Fri, 14 Feb 2014 15:54:00 +0900 Message-Id: <1392360843-22261-3-git-send-email-iamjoonsoo.kim@lge.com> In-Reply-To: <1392360843-22261-1-git-send-email-iamjoonsoo.kim@lge.com> References: <1392360843-22261-1-git-send-email-iamjoonsoo.kim@lge.com> Sender: owner-linux-mm@kvack.org List-ID: To: Andrew Morton Cc: Mel Gorman , Vlastimil Babka , Joonsoo Kim , Rik van Riel , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joonsoo Kim suitable_migration_target() checks that pageblock is suitable for migration target. In isolate_freepages_block(), it is called on every page and this is inefficient. So make it called once per pageblock. suitable_migration_target() also checks if page is highorder or not, but it's criteria for highorder is pageblock order. So calling it once within pageblock range has no problem. Signed-off-by: Joonsoo Kim diff --git a/mm/compaction.c b/mm/compaction.c index bbe1260..0d821a2 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -245,6 +245,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, unsigned long nr_strict_required = end_pfn - blockpfn; unsigned long flags; bool locked = false; + bool checked_pageblock = false; cursor = pfn_to_page(blockpfn); @@ -275,8 +276,16 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, break; /* Recheck this is a suitable migration target under lock */ - if (!strict && !suitable_migration_target(page)) - break; + if (!strict && !checked_pageblock) { + /* + * We need to check suitability of pageblock only once + * and this isolate_freepages_block() is called with + * pageblock range, so just check once is sufficient. + */ + checked_pageblock = true; + if (!suitable_migration_target(page)) + break; + } /* Recheck this is a buddy page under lock */ if (!PageBuddy(page)) -- 1.7.9.5 -- 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