From 49255c619fbd482d704289b5eb2795f8e3b7ff2e Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 16 Jun 2009 15:31:58 -0700 Subject: [PATCH] page allocator: move check for disabled anti-fragmentation out of fastpath 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 Reviewed-by: Christoph Lameter Reviewed-by: KOSAKI Motohiro Cc: Pekka Enberg Cc: Peter Zijlstra Cc: Nick Piggin Cc: Dave Hansen Cc: Lee Schermerhorn Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 a47c879e1304..0aa4445b0b8a 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 512bf9a618c7..b09859629e93 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -168,6 +168,10 @@ 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); } -- 2.39.2