Index: linux-2.6/mm/vmscan.c
===================================================================
--- linux-2.6.orig/mm/vmscan.c
+++ linux-2.6/mm/vmscan.c
@@ -511,7 +511,12 @@ static int shrink_list(struct list_head 
 		 * 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)) {
+		if (page_count(page) != 2) {
+			write_unlock_irq(&mapping->tree_lock);
+			goto keep_locked;
+		}
+		smp_rmb();
+		if (PageDirty(page)) {
 			write_unlock_irq(&mapping->tree_lock);
 			goto keep_locked;
 		}