From 46dafbca2bba811665b01d8cedf911204820623c Mon Sep 17 00:00:00 2001 From: Mel Gorman Date: Tue, 16 Oct 2007 01:25:55 -0700 Subject: [PATCH] Be more agressive about stealing when MIGRATE_RECLAIMABLE allocations fallback MIGRATE_RECLAIMABLE allocations tend to be very bursty in nature like when updatedb starts. It is likely this will occur in situations where MAX_ORDER blocks of pages are not free. This means that updatedb can scatter MIGRATE_RECLAIMABLE pages throughout the address space. This patch is more agressive about stealing blocks of pages for MIGRATE_RECLAIMABLE. Signed-off-by: Mel Gorman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/page_alloc.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index e1d87ee1d9c6..b864584c92b4 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -821,11 +821,23 @@ static struct page *__rmqueue_fallback(struct zone *zone, int order, /* * If breaking a large block of pages, move all free - * pages to the preferred allocation list + * pages to the preferred allocation list. If falling + * back for a reclaimable kernel allocation, be more + * agressive about taking ownership of free pages */ - if (unlikely(current_order >= MAX_ORDER / 2)) { + if (unlikely(current_order >= MAX_ORDER / 2) || + start_migratetype == MIGRATE_RECLAIMABLE) { + unsigned long pages; + pages = move_freepages_block(zone, page, + start_migratetype); + + /* Claim the whole block if over half of it is free */ + if ((pages << current_order) >= (1 << (MAX_ORDER-2)) && + migratetype != MIGRATE_HIGHATOMIC) + set_pageblock_migratetype(page, + start_migratetype); + migratetype = start_migratetype; - move_freepages_block(zone, page, migratetype); } /* Remove the page from the freelists */ -- GitLab