diff options
-rw-r--r-- | include/linux/mm.h | 19 | ||||
-rw-r--r-- | mm/vmscan.c | 25 |
2 files changed, 22 insertions, 22 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 498ff8778fb6..b12d5c76420d 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h | |||
@@ -301,17 +301,20 @@ struct page { | |||
301 | * Drop a ref, return true if the logical refcount fell to zero (the page has | 301 | * Drop a ref, return true if the logical refcount fell to zero (the page has |
302 | * no users) | 302 | * no users) |
303 | */ | 303 | */ |
304 | #define put_page_testzero(p) \ | 304 | static inline int put_page_testzero(struct page *page) |
305 | ({ \ | 305 | { |
306 | BUG_ON(atomic_read(&(p)->_count) == -1);\ | 306 | BUG_ON(atomic_read(&page->_count) == -1); |
307 | atomic_add_negative(-1, &(p)->_count); \ | 307 | return atomic_add_negative(-1, &page->_count); |
308 | }) | 308 | } |
309 | 309 | ||
310 | /* | 310 | /* |
311 | * Grab a ref, return true if the page previously had a logical refcount of | 311 | * Try to grab a ref unless the page has a refcount of zero, return false if |
312 | * zero. ie: returns true if we just grabbed an already-deemed-to-be-free page | 312 | * that is the case. |
313 | */ | 313 | */ |
314 | #define get_page_testone(p) atomic_inc_and_test(&(p)->_count) | 314 | static inline int get_page_unless_zero(struct page *page) |
315 | { | ||
316 | return atomic_add_unless(&page->_count, 1, -1); | ||
317 | } | ||
315 | 318 | ||
316 | #define set_page_count(p,v) atomic_set(&(p)->_count, (v) - 1) | 319 | #define set_page_count(p,v) atomic_set(&(p)->_count, (v) - 1) |
317 | #define __put_page(p) atomic_dec(&(p)->_count) | 320 | #define __put_page(p) atomic_dec(&(p)->_count) |
diff --git a/mm/vmscan.c b/mm/vmscan.c index 8e477b1a4838..e21bab4deda6 100644 --- a/mm/vmscan.c +++ b/mm/vmscan.c | |||
@@ -1083,29 +1083,26 @@ static int isolate_lru_pages(int nr_to_scan, struct list_head *src, | |||
1083 | int scan = 0; | 1083 | int scan = 0; |
1084 | 1084 | ||
1085 | while (scan++ < nr_to_scan && !list_empty(src)) { | 1085 | while (scan++ < nr_to_scan && !list_empty(src)) { |
1086 | struct list_head *target; | ||
1086 | page = lru_to_page(src); | 1087 | page = lru_to_page(src); |
1087 | prefetchw_prev_lru_page(page, src, flags); | 1088 | prefetchw_prev_lru_page(page, src, flags); |
1088 | 1089 | ||
1089 | BUG_ON(!PageLRU(page)); | 1090 | BUG_ON(!PageLRU(page)); |
1090 | 1091 | ||
1091 | list_del(&page->lru); | 1092 | list_del(&page->lru); |
1092 | if (unlikely(get_page_testone(page))) { | 1093 | target = src; |
1094 | if (likely(get_page_unless_zero(page))) { | ||
1093 | /* | 1095 | /* |
1094 | * It is being freed elsewhere | 1096 | * Be careful not to clear PageLRU until after we're |
1097 | * sure the page is not being freed elsewhere -- the | ||
1098 | * page release code relies on it. | ||
1095 | */ | 1099 | */ |
1096 | __put_page(page); | 1100 | ClearPageLRU(page); |
1097 | list_add(&page->lru, src); | 1101 | target = dst; |
1098 | continue; | 1102 | nr_taken++; |
1099 | } | 1103 | } /* else it is being freed elsewhere */ |
1100 | 1104 | ||
1101 | /* | 1105 | list_add(&page->lru, target); |
1102 | * Be careful not to clear PageLRU until after we're sure | ||
1103 | * the page is not being freed elsewhere -- the page release | ||
1104 | * code relies on it. | ||
1105 | */ | ||
1106 | ClearPageLRU(page); | ||
1107 | list_add(&page->lru, dst); | ||
1108 | nr_taken++; | ||
1109 | } | 1106 | } |
1110 | 1107 | ||
1111 | *scanned = scan; | 1108 | *scanned = scan; |