1 files changed, 18 insertions, 6 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 791b00ca4e8b..2ff0289ad061 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -4077,9 +4077,9 @@ static struct cftype mem_cgroup_legacy_files[] = {
 
 static DEFINE_IDR(mem_cgroup_idr);
 
-static void mem_cgroup_id_get(struct mem_cgroup *memcg)
+static void mem_cgroup_id_get_many(struct mem_cgroup *memcg, unsigned int n)
 {
-	atomic_inc(&memcg->id.ref);
+	atomic_add(n, &memcg->id.ref);
 }
 
 static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg)
@@ -4100,9 +4100,9 @@ static struct mem_cgroup *mem_cgroup_id_get_online(struct mem_cgroup *memcg)
 	return memcg;
 }
 
-static void mem_cgroup_id_put(struct mem_cgroup *memcg)
+static void mem_cgroup_id_put_many(struct mem_cgroup *memcg, unsigned int n)
 {
-	if (atomic_dec_and_test(&memcg->id.ref)) {
+	if (atomic_sub_and_test(n, &memcg->id.ref)) {
 		idr_remove(&mem_cgroup_idr, memcg->id.id);
 		memcg->id.id = 0;
 
@@ -4111,6 +4111,16 @@ static void mem_cgroup_id_put(struct mem_cgroup *memcg)
 	}
 }
 
+static inline void mem_cgroup_id_get(struct mem_cgroup *memcg)
+{
+	mem_cgroup_id_get_many(memcg, 1);
+}
+
+static inline void mem_cgroup_id_put(struct mem_cgroup *memcg)
+{
+	mem_cgroup_id_put_many(memcg, 1);
+}
+
 /**
  * mem_cgroup_from_id - look up a memcg from a memcg id
  * @id: the memcg id to look up
@@ -4745,6 +4755,8 @@ static void __mem_cgroup_clear_mc(void)
 		if (!mem_cgroup_is_root(mc.from))
 			page_counter_uncharge(&mc.from->memsw, mc.moved_swap);
 
+		mem_cgroup_id_put_many(mc.from, mc.moved_swap);
+
 		/*
 		 * we charged both to->memory and to->memsw, so we
 		 * should uncharge to->memory.
@@ -4752,9 +4764,9 @@ static void __mem_cgroup_clear_mc(void)
 		if (!mem_cgroup_is_root(mc.to))
 			page_counter_uncharge(&mc.to->memory, mc.moved_swap);
 
-		css_put_many(&mc.from->css, mc.moved_swap);
+		mem_cgroup_id_get_many(mc.to, mc.moved_swap);
+		css_put_many(&mc.to->css, mc.moved_swap);
 
-		/* we've already done css_get(mc.to) */
 		mc.moved_swap = 0;
 	}
 	memcg_oom_recover(from);