From 95e3441248053fc06bbb1dbbd34409a84211619e Mon Sep 17 00:00:00 2001 From: Minchan Kim Date: Mon, 8 Oct 2012 16:32:11 -0700 Subject: [PATCH] mm: remain migratetype in freed page The page allocator caches the pageblock information in page->private while it is in the PCP freelists but this is overwritten with the order of the page when freed to the buddy allocator. This patch stores the migratetype of the page in the page->index field so that it is available at all times when the page remain in free_list. This patch adds a new call site in __free_pages_ok so it might be overhead a bit but it's for high order allocation. So I believe damage isn't hurt. Signed-off-by: Minchan Kim Acked-by: KAMEZAWA Hiroyuki Reviewed-by: Yasuaki Ishimatsu Acked-by: Mel Gorman Cc: Xishi Qiu Cc: Wen Congyang Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mm.h | 4 ++-- mm/page_alloc.c | 7 +++++-- 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 4ed5c7367b9b..b01e585ab4b5 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -240,13 +240,13 @@ struct inode; /* It's valid only if the page is free path or free_list */ static inline void set_freepage_migratetype(struct page *page, int migratetype) { - set_page_private(page, migratetype); + page->index = migratetype; } /* It's valid only if the page is free path or free_list */ static inline int get_freepage_migratetype(struct page *page) { - return page_private(page); + return page->index; } /* diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 6aa0a8e89c5d..94fd283dde98 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -729,6 +729,7 @@ static void __free_pages_ok(struct page *page, unsigned int order) { unsigned long flags; int wasMlocked = __TestClearPageMlocked(page); + int migratetype; if (!free_pages_prepare(page, order)) return; @@ -737,8 +738,9 @@ static void __free_pages_ok(struct page *page, unsigned int order) if (unlikely(wasMlocked)) free_page_mlock(page); __count_vm_events(PGFREE, 1 << order); - free_one_page(page_zone(page), page, order, - get_pageblock_migratetype(page)); + migratetype = get_pageblock_migratetype(page); + set_freepage_migratetype(page, migratetype); + free_one_page(page_zone(page), page, order, migratetype); local_irq_restore(flags); } @@ -959,6 +961,7 @@ static int move_freepages(struct zone *zone, order = page_order(page); list_move(&page->lru, &zone->free_area[order].free_list[migratetype]); + set_freepage_migratetype(page, migratetype); page += 1 << order; pages_moved += 1 << order; }