---
 mm/memcontrol.c |   26 +++++++-------------------
 1 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index a2677e0..7424fab 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c

@@ -3168,6 +3168,7 @@ int mem_cgroup_prepare_migration(struct page *page,
 	struct page *newpage, struct mem_cgroup **memcgp, gfp_t gfp_mask)
 {
 	struct mem_cgroup *memcg = NULL;
+	struct res_counter *dummy;
 	struct page_cgroup *pc;
 	enum charge_type ctype;
 	int ret = 0;

@@ -3222,29 +3223,16 @@ int mem_cgroup_prepare_migration(struct page *page,
 	 */
 	if (!memcg)
 		return 0;
-
-	*memcgp = memcg;
-	ret = __mem_cgroup_try_charge(NULL, gfp_mask, 1, memcgp, false);
-	css_put(&memcg->css);/* drop extra refcnt */
-	if (ret) {
-		if (PageAnon(page)) {
-			lock_page_cgroup(pc);
-			ClearPageCgroupMigration(pc);
-			unlock_page_cgroup(pc);
-			/*
-			 * The old page may be fully unmapped while we kept it.
-			 */
-			mem_cgroup_uncharge_page(page);
-		}
-		/* we'll need to revisit this error code (we have -EINTR) */
-		return -ENOMEM;
-	}
 	/*
 	 * We charge new page before it's used/mapped. So, even if unlock_page()
 	 * is called before end_migration, we can catch all events on this new
 	 * page. In the case new page is migrated but not remapped, new page's
 	 * mapcount will be finally 0 and we call uncharge in end_migration().
 	 */
+	res_counter_charge_nofail(&memcg->res, PAGE_SIZE, &dummy);
+	if (do_swap_account)
+		res_counter_charge_nofail(&memcg->memsw, PAGE_SIZE, &dummy);
+
 	if (PageAnon(page))
 		ctype = MEM_CGROUP_CHARGE_TYPE_ANON;
 	else if (page_is_file_cache(page))

@@ -3807,9 +3795,9 @@ static inline u64 mem_cgroup_usage(struct mem_cgroup *memcg, bool swap)
 
 	if (!mem_cgroup_is_root(memcg)) {
 		if (!swap)
-			return res_counter_read_u64(&memcg->res, RES_USAGE);
+			return res_counter_usage_safe(&memcg->res);
 		else
-			return res_counter_read_u64(&memcg->memsw, RES_USAGE);
+			return res_counter_usage_safe(&memcg->memsw);
 	}
 
 	val = mem_cgroup_recursive_stat(memcg, MEM_CGROUP_STAT_CACHE);

-- 
1.7.4.1