diff --git a/kernel/cgroup/cpuset.c b/kernel/cgroup/cpuset.c index d43d25acc95a..153628277a48 100644 --- a/kernel/cgroup/cpuset.c +++ b/kernel/cgroup/cpuset.c @@ -1528,9 +1528,13 @@ static void cpuset_attach(struct cgroup_taskset *tset) cgroup_taskset_first(tset, &css); cs = css_cs(css); - cpus_read_lock(); mutex_lock(&cpuset_mutex); + /* + * It should hold cpus lock because a cpu offline event can + * cause set_cpus_allowed_ptr() failed. + */ + get_online_cpus(); /* prepare for attach */ if (cs == &top_cpuset) cpumask_copy(cpus_attach, cpu_possible_mask); @@ -1549,6 +1553,7 @@ static void cpuset_attach(struct cgroup_taskset *tset) cpuset_change_task_nodemask(task, &cpuset_attach_nodemask_to); cpuset_update_task_spread_flag(cs, task); } + put_online_cpus(); /* * Change mm for all threadgroup leaders. This is expensive and may @@ -1584,7 +1589,6 @@ static void cpuset_attach(struct cgroup_taskset *tset) wake_up(&cpuset_attach_wq); mutex_unlock(&cpuset_mutex); - cpus_read_unlock(); } /* The various types of files and directories in a cpuset file system */