1 files changed, 7 insertions, 3 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index a841b5c01ef9..6012e326e856 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -1338,10 +1338,14 @@ static void cpuset_attach(struct cgroup_subsys *ss,
         struct cpuset *oldcs = cgroup_cs(oldcont);
         int err;
 
-        mutex_lock(&callback_mutex);
-        guarantee_online_cpus(cs, &cpus);
+        if (cs == &top_cpuset) {
+                cpus = cpu_possible_map;
+        } else {
+                mutex_lock(&callback_mutex);
+                guarantee_online_cpus(cs, &cpus);
+                mutex_unlock(&callback_mutex);
+        }
         err = set_cpus_allowed_ptr(tsk, &cpus);
-        mutex_unlock(&callback_mutex);
         if (err)
                 return;