1 files changed, 2 insertions, 0 deletions

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 1c52ddbc839b..5335b2b6be77 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -866,6 +866,7 @@ static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
         unsigned long val = 0;
         int cpu;
 
+        get_online_cpus();
         for_each_online_cpu(cpu)
                 val += per_cpu(memcg->stat->events[idx], cpu);
 #ifdef CONFIG_HOTPLUG_CPU
@@ -873,6 +874,7 @@ static unsigned long mem_cgroup_read_events(struct mem_cgroup *memcg,
         val += memcg->nocpu_base.events[idx];
         spin_unlock(&memcg->pcp_counter_lock);
 #endif
+        put_online_cpus();
         return val;
 }