diff options
Diffstat (limited to 'mm/page_alloc.c')
| -rw-r--r-- | mm/page_alloc.c | 31 |
1 files changed, 18 insertions, 13 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index dc523a1f270d..b8165e037dee 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -151,7 +151,8 @@ static void bad_page(struct page *page) 1 << PG_reclaim | 1 << PG_slab | 1 << PG_swapcache | - 1 << PG_writeback ); + 1 << PG_writeback | + 1 << PG_buddy ); set_page_count(page, 0); reset_page_mapcount(page); page->mapping = NULL; @@ -236,12 +237,12 @@ static inline unsigned long page_order(struct page *page) { static inline void set_page_order(struct page *page, int order) { set_page_private(page, order); - __SetPagePrivate(page); + __SetPageBuddy(page); } static inline void rmv_page_order(struct page *page) { - __ClearPagePrivate(page); + __ClearPageBuddy(page); set_page_private(page, 0); } @@ -280,11 +281,13 @@ __find_combined_index(unsigned long page_idx, unsigned int order) * This function checks whether a page is free && is the buddy * we can do coalesce a page and its buddy if * (a) the buddy is not in a hole && - * (b) the buddy is free && - * (c) the buddy is on the buddy system && - * (d) a page and its buddy have the same order. - * for recording page's order, we use page_private(page) and PG_private. + * (b) the buddy is in the buddy system && + * (c) a page and its buddy have the same order. + * + * For recording whether a page is in the buddy system, we use PG_buddy. + * Setting, clearing, and testing PG_buddy is serialized by zone->lock. * + * For recording page's order, we use page_private(page). */ static inline int page_is_buddy(struct page *page, int order) { @@ -293,10 +296,10 @@ static inline int page_is_buddy(struct page *page, int order) return 0; #endif - if (PagePrivate(page) && - (page_order(page) == order) && - page_count(page) == 0) + if (PageBuddy(page) && page_order(page) == order) { + BUG_ON(page_count(page) != 0); return 1; + } return 0; } @@ -313,7 +316,7 @@ static inline int page_is_buddy(struct page *page, int order) * as necessary, plus some accounting needed to play nicely with other * parts of the VM system. * At each level, we keep a list of pages, which are heads of continuous - * free pages of length of (1 << order) and marked with PG_Private.Page's + * free pages of length of (1 << order) and marked with PG_buddy. Page's * order is recorded in page_private(page) field. * So when we are allocating or freeing one, we can derive the state of the * other. That is, if we allocate a small block, and both were @@ -376,7 +379,8 @@ static inline int free_pages_check(struct page *page) 1 << PG_slab | 1 << PG_swapcache | 1 << PG_writeback | - 1 << PG_reserved )))) + 1 << PG_reserved | + 1 << PG_buddy )))) bad_page(page); if (PageDirty(page)) __ClearPageDirty(page); @@ -524,7 +528,8 @@ static int prep_new_page(struct page *page, int order, gfp_t gfp_flags) 1 << PG_slab | 1 << PG_swapcache | 1 << PG_writeback | - 1 << PG_reserved )))) + 1 << PG_reserved | + 1 << PG_buddy )))) bad_page(page); /* |