---

yaml --- r: 320792 b: refs/heads/master c: 97d255c h: refs/heads/master v: v3
git-mirror · Aug 1, 2012 · 5322cce · 5322cce
1 parent 7013e33
commit 5322cce
Show file tree

Hide file tree

Showing 2 changed files with 9 additions and 2 deletions.
diff --git a/[refs] b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: de34d965a80d0f61a354bdefa0b15a88bcff2028
+refs/heads/master: 97d255c816946388bab504122937730d3447c612
diff --git a/trunk/mm/page_alloc.c b/trunk/mm/page_alloc.c
@@ -5500,11 +5500,18 @@ __count_immobile_pages(struct zone *zone, struct page *page, int count)
 			continue;
 
 		page = pfn_to_page(check);
-		if (!page_count(page)) {
+		/*
+		 * We can't use page_count without pin a page
+		 * because another CPU can free compound page.
+		 * This check already skips compound tails of THP
+		 * because their page->_count is zero at all time.
+		 */
+		if (!atomic_read(&page->_count)) {
 			if (PageBuddy(page))
 				iter += (1 << page_order(page)) - 1;
 			continue;
 		}
+
 		if (!PageLRU(page))
 			found++;
 		/*