[PATCH] Page Migration: Make do_swap_page redo the fault

[karo-tx-linux.git] / mm / page_alloc.c

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 253a450c400df06898de5d864ff2c8863c560043..fd631c2536a5e67de95331d93afbf6853ceee6fe 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -286,22 +286,27 @@ __find_combined_index(unsigned long page_idx, unsigned int order)
  * we can do coalesce a page and its buddy if
  * (a) the buddy is not in a hole &&
  * (b) the buddy is in the buddy system &&
- * (c) a page and its buddy have the same order.
+ * (c) a page and its buddy have the same order &&
+ * (d) a page and its buddy are in the same zone.
  *
  * 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)
+static inline int page_is_buddy(struct page *page, struct page *buddy,
+                                                               int order)
 {
 #ifdef CONFIG_HOLES_IN_ZONE
-       if (!pfn_valid(page_to_pfn(page)))
+       if (!pfn_valid(page_to_pfn(buddy)))
                return 0;
 #endif
 
-       if (PageBuddy(page) && page_order(page) == order) {
-               BUG_ON(page_count(page) != 0);
+       if (page_zone_id(page) != page_zone_id(buddy))
+               return 0;
+
+       if (PageBuddy(buddy) && page_order(buddy) == order) {
+               BUG_ON(page_count(buddy) != 0);
                return 1;
        }
        return 0;
@@ -352,7 +357,7 @@ static inline void __free_one_page(struct page *page,
                struct page *buddy;
 
                buddy = __page_find_buddy(page, page_idx, order);
-               if (!page_is_buddy(buddy, order))
+               if (!page_is_buddy(page, buddy, order))
                        break;          /* Move the buddy up one level. */
 
                list_del(&buddy->lru);