Page allocator doesn't keep migratetype information to page when the page is freed. This patch remains the information to freed page's index field which isn't used by free/alloc preparing so it shouldn't change any behavir except below one. 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 <minchan@xxxxxxxxxx> --- include/linux/mm.h | 6 ++++-- mm/page_alloc.c | 7 ++++--- 2 files changed, 8 insertions(+), 5 deletions(-) diff --git a/include/linux/mm.h b/include/linux/mm.h index 86d61d6..8fd32da 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -251,12 +251,14 @@ struct inode; static inline void set_page_migratetype(struct page *page, int migratetype) { - set_page_private(page, migratetype); + VM_BUG_ON((unsigned int)migratetype >= MIGRATE_TYPES); + page->index = migratetype; } static inline int get_page_migratetype(struct page *page) { - return page_private(page); + VM_BUG_ON((unsigned int)page->index >= MIGRATE_TYPES); + return page->index; } /* diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 103ba66..32985dd 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -723,6 +723,7 @@ 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; @@ -731,9 +732,9 @@ 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_page_migratetype(page, migratetype); + free_one_page(page_zone(page), page, order, migratetype); local_irq_restore(flags); } -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>