cgroup: remove rcu_read_lock()/rcu_read_unlock() in critical section of spin_lock_irq()

spin_lock_irq() already disable preempt, so remove rcu_read_lock().

Signed-off-by: Ran Tian <tianran_trtr@163.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

diff --git a/kernel/cgroup/cgroup.c b/kernel/cgroup/cgroup.c
index f2743a4..3028f6b 100644 (file)
--- a/kernel/cgroup/cgroup.c
+++ b/kernel/cgroup/cgroup.c
@@ -2866,14 +2866,12 @@ int cgroup_migrate(struct task_struct *leader, bool threadgroup,
         * take an rcu_read_lock.
         */
        spin_lock_irq(&css_set_lock);
-       rcu_read_lock();
        task = leader;
        do {
                cgroup_migrate_add_task(task, mgctx);
                if (!threadgroup)
                        break;
        } while_each_thread(leader, task);
-       rcu_read_unlock();
        spin_unlock_irq(&css_set_lock);
 
        return cgroup_migrate_execute(mgctx);