On architectures that allow memory holes, page_is_buddy() has to perform page_to_pfn() to check for the memory hole. After the previous patch, we have the pfn already available in __free_one_page(), which is the only caller of page_is_buddy(), so move the check there and avoid page_to_pfn().
Signed-off-by: Vlastimil Babka <[email protected]> --- mm/page_alloc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 812475bff8f3..6ba0782f7892 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -714,7 +714,7 @@ static inline void rmv_page_order(struct page *page) /* * 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 && + * (a) the buddy is not in a hole (check before calling!) && * (b) the buddy is in the buddy system && * (c) a page and its buddy have the same order && * (d) a page and its buddy are in the same zone. @@ -729,9 +729,6 @@ static inline void rmv_page_order(struct page *page) static inline int page_is_buddy(struct page *page, struct page *buddy, unsigned int order) { - if (!pfn_valid_within(page_to_pfn(buddy))) - return 0; - if (page_is_guard(buddy) && page_order(buddy) == order) { if (page_zone_id(page) != page_zone_id(buddy)) return 0; @@ -808,6 +805,9 @@ static inline void __free_one_page(struct page *page, while (order < max_order - 1) { buddy_pfn = __find_buddy_pfn(page_pfn, order); buddy = page + (buddy_pfn - page_pfn); + + if (!pfn_valid_within(buddy_pfn)) + goto done_merging; if (!page_is_buddy(page, buddy, order)) goto done_merging; /* @@ -862,7 +862,7 @@ static inline void __free_one_page(struct page *page, * so it's less likely to be used soon and more likely to be merged * as a higher order page */ - if ((order < MAX_ORDER-2) && pfn_valid_within(page_to_pfn(buddy))) { + if ((order < MAX_ORDER-2) && pfn_valid_within(buddy_pfn)) { struct page *higher_page, *higher_buddy; combined_pfn = buddy_pfn & page_pfn; higher_page = page + (combined_pfn - page_pfn); -- 2.11.0
