From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id 3A9BC6B0085 for ; Sun, 22 Feb 2009 18:16:30 -0500 (EST) From: Mel Gorman Subject: [PATCH 08/20] Move check for disabled anti-fragmentation out of fastpath Date: Sun, 22 Feb 2009 23:17:17 +0000 Message-Id: <1235344649-18265-9-git-send-email-mel@csn.ul.ie> In-Reply-To: <1235344649-18265-1-git-send-email-mel@csn.ul.ie> References: <1235344649-18265-1-git-send-email-mel@csn.ul.ie> Sender: owner-linux-mm@kvack.org To: Mel Gorman , Linux Memory Management List Cc: Pekka Enberg , Rik van Riel , KOSAKI Motohiro , Christoph Lameter , Johannes Weiner , Nick Piggin , Linux Kernel Mailing List , Lin Ming , Zhang Yanmin List-ID: On low-memory systems, anti-fragmentation gets disabled as there is nothing it can do and it would just incur overhead shuffling pages between lists constantly. Currently the check is made in the free page fast path for every page. This patch moves it to a slow path. On machines with low memory, there will be small amount of additional overhead as pages get shuffled between lists but it should quickly settle. Signed-off-by: Mel Gorman --- include/linux/mmzone.h | 3 --- mm/page_alloc.c | 4 ++++ 2 files changed, 4 insertions(+), 3 deletions(-) diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h index 09c14e2..6089393 100644 --- a/include/linux/mmzone.h +++ b/include/linux/mmzone.h @@ -50,9 +50,6 @@ extern int page_group_by_mobility_disabled; static inline int get_pageblock_migratetype(struct page *page) { - if (unlikely(page_group_by_mobility_disabled)) - return MIGRATE_UNMOVABLE; - return get_pageblock_flags_group(page, PB_migrate, PB_migrate_end); } diff --git a/mm/page_alloc.c b/mm/page_alloc.c index dc50c47..eaa0ab7 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -172,6 +172,10 @@ int page_group_by_mobility_disabled __read_mostly; static void set_pageblock_migratetype(struct page *page, int migratetype) { + + if (unlikely(page_group_by_mobility_disabled)) + migratetype = MIGRATE_UNMOVABLE; + set_pageblock_flags_group(page, (unsigned long)migratetype, PB_migrate, PB_migrate_end); } -- 1.5.6.5 -- 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