From 47118af076f64844b4f423bc2f545b2da9dab50d Mon Sep 17 00:00:00 2001 From: Michal Nazarewicz Date: Thu, 29 Dec 2011 13:09:50 +0100 Subject: mm: mmzone: MIGRATE_CMA migration type added The MIGRATE_CMA migration type has two main characteristics: (i) only movable pages can be allocated from MIGRATE_CMA pageblocks and (ii) page allocator will never change migration type of MIGRATE_CMA pageblocks. This guarantees (to some degree) that page in a MIGRATE_CMA page block can always be migrated somewhere else (unless there's no memory left in the system). It is designed to be used for allocating big chunks (eg. 10MiB) of physically contiguous memory. Once driver requests contiguous memory, pages from MIGRATE_CMA pageblocks may be migrated away to create a contiguous block. To minimise number of migrations, MIGRATE_CMA migration type is the last type tried when page allocator falls back to other migration types when requested. Signed-off-by: Michal Nazarewicz Signed-off-by: Marek Szyprowski Signed-off-by: Kyungmin Park Acked-by: Mel Gorman Reviewed-by: KAMEZAWA Hiroyuki Tested-by: Rob Clark Tested-by: Ohad Ben-Cohen Tested-by: Benjamin Gaignard Tested-by: Robert Nelson Tested-by: Barry Song --- mm/compaction.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'mm/compaction.c') diff --git a/mm/compaction.c b/mm/compaction.c index 7a92e418a187..da7d35ea5103 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -45,6 +45,11 @@ static void map_pages(struct list_head *list) } } +static inline bool migrate_async_suitable(int migratetype) +{ + return is_migrate_cma(migratetype) || migratetype == MIGRATE_MOVABLE; +} + /* * Isolate free pages onto a private freelist. Caller must hold zone->lock. * If @strict is true, will abort returning 0 on any invalid PFNs or non-free @@ -299,7 +304,7 @@ isolate_migratepages_range(struct zone *zone, struct compact_control *cc, */ pageblock_nr = low_pfn >> pageblock_order; if (!cc->sync && last_pageblock_nr != pageblock_nr && - get_pageblock_migratetype(page) != MIGRATE_MOVABLE) { + !migrate_async_suitable(get_pageblock_migratetype(page))) { low_pfn += pageblock_nr_pages; low_pfn = ALIGN(low_pfn, pageblock_nr_pages) - 1; last_pageblock_nr = pageblock_nr; @@ -367,8 +372,8 @@ static bool suitable_migration_target(struct page *page) if (PageBuddy(page) && page_order(page) >= pageblock_order) return true; - /* If the block is MIGRATE_MOVABLE, allow migration */ - if (migratetype == MIGRATE_MOVABLE) + /* If the block is MIGRATE_MOVABLE or MIGRATE_CMA, allow migration */ + if (migrate_async_suitable(migratetype)) return true; /* Otherwise skip the block */ -- cgit v1.2.2