{
struct mem_cgroup *memcg = mem_cgroup_from_cont(cgrp);
struct mem_cgroup *parent;
+
if (val > 100)
return -EINVAL;
return -EINVAL;
parent = mem_cgroup_from_cont(cgrp->parent);
+
+ cgroup_lock();
+
/* If under hierarchy, only empty-root can set this value */
if ((parent->use_hierarchy) ||
- (memcg->use_hierarchy && !list_empty(&cgrp->children)))
+ (memcg->use_hierarchy && !list_empty(&cgrp->children))) {
+ cgroup_unlock();
return -EINVAL;
+ }
spin_lock(&memcg->reclaim_param_lock);
memcg->swappiness = val;
spin_unlock(&memcg->reclaim_param_lock);
+ cgroup_unlock();
+
return 0;
}