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-rw-r--r--mm/page_alloc.c17
1 files changed, 11 insertions, 6 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 253a450c400d..fd631c2536a5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -286,22 +286,27 @@ __find_combined_index(unsigned long page_idx, unsigned int order)
286 * we can do coalesce a page and its buddy if 286 * we can do coalesce a page and its buddy if
287 * (a) the buddy is not in a hole && 287 * (a) the buddy is not in a hole &&
288 * (b) the buddy is in the buddy system && 288 * (b) the buddy is in the buddy system &&
289 * (c) a page and its buddy have the same order. 289 * (c) a page and its buddy have the same order &&
290 * (d) a page and its buddy are in the same zone.
290 * 291 *
291 * For recording whether a page is in the buddy system, we use PG_buddy. 292 * For recording whether a page is in the buddy system, we use PG_buddy.
292 * Setting, clearing, and testing PG_buddy is serialized by zone->lock. 293 * Setting, clearing, and testing PG_buddy is serialized by zone->lock.
293 * 294 *
294 * For recording page's order, we use page_private(page). 295 * For recording page's order, we use page_private(page).
295 */ 296 */
296static inline int page_is_buddy(struct page *page, int order) 297static inline int page_is_buddy(struct page *page, struct page *buddy,
298 int order)
297{ 299{
298#ifdef CONFIG_HOLES_IN_ZONE 300#ifdef CONFIG_HOLES_IN_ZONE
299 if (!pfn_valid(page_to_pfn(page))) 301 if (!pfn_valid(page_to_pfn(buddy)))
300 return 0; 302 return 0;
301#endif 303#endif
302 304
303 if (PageBuddy(page) && page_order(page) == order) { 305 if (page_zone_id(page) != page_zone_id(buddy))
304 BUG_ON(page_count(page) != 0); 306 return 0;
307
308 if (PageBuddy(buddy) && page_order(buddy) == order) {
309 BUG_ON(page_count(buddy) != 0);
305 return 1; 310 return 1;
306 } 311 }
307 return 0; 312 return 0;
@@ -352,7 +357,7 @@ static inline void __free_one_page(struct page *page,
352 struct page *buddy; 357 struct page *buddy;
353 358
354 buddy = __page_find_buddy(page, page_idx, order); 359 buddy = __page_find_buddy(page, page_idx, order);
355 if (!page_is_buddy(buddy, order)) 360 if (!page_is_buddy(page, buddy, order))
356 break; /* Move the buddy up one level. */ 361 break; /* Move the buddy up one level. */
357 362
358 list_del(&buddy->lru); 363 list_del(&buddy->lru);