From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755096AbaH1TFP (ORCPT ); Thu, 28 Aug 2014 15:05:15 -0400 Received: from cantor2.suse.de ([195.135.220.15]:32855 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752196AbaH1SgS (ORCPT ); Thu, 28 Aug 2014 14:36:18 -0400 From: Mel Gorman To: Jiri Slaby Cc: Linux-Stable , LKML , Mel Gorman Subject: [PATCH 29/97] mm/compaction: do not call suitable_migration_target() on every page Date: Thu, 28 Aug 2014 19:34:37 +0100 Message-Id: <1409250945-30874-30-git-send-email-mgorman@suse.de> X-Mailer: git-send-email 1.8.4.5 In-Reply-To: <1409250945-30874-1-git-send-email-mgorman@suse.de> References: <1409250945-30874-1-git-send-email-mgorman@suse.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Joonsoo Kim commit 01ead5340bcf5f3a1cd2452c75516d0ef4d908d7 upstream. 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 Acked-by: Vlastimil Babka Cc: Mel Gorman Cc: Rik van Riel Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Mel Gorman --- mm/compaction.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/mm/compaction.c b/mm/compaction.c index 5e48834..6718a91 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -245,6 +245,7 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, struct page *cursor, *valid_page = NULL; unsigned long flags; bool locked = false; + bool checked_pageblock = false; cursor = pfn_to_page(blockpfn); @@ -276,8 +277,16 @@ 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)) -- 1.8.4.5