Merge master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6

[powerpc.git] / mm / vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index 0ea71e8..64f9570 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -511,10 +511,11 @@ static int shrink_list(struct list_head *page_list, struct scan_control *sc)
                 * PageDirty _after_ making sure that the page is freeable and
                 * not in use by anybody.       (pagecache + us == 2)
                 */
-               if (page_count(page) != 2 || PageDirty(page)) {
-                       write_unlock_irq(&mapping->tree_lock);
-                       goto keep_locked;
-               }
+               if (unlikely(page_count(page) != 2))
+                       goto cannot_free;
+               smp_rmb();
+               if (unlikely(PageDirty(page)))
+                       goto cannot_free;
 
 #ifdef CONFIG_SWAP
                if (PageSwapCache(page)) {
@@ -538,6 +539,10 @@ free_it:
                        __pagevec_release_nonlru(&freed_pvec);
                continue;
 
+cannot_free:
+               write_unlock_irq(&mapping->tree_lock);
+               goto keep_locked;
+
 activate_locked:
                SetPageActive(page);
                pgactivate++;