kthread: call wake_up_process() without the lock being held

From the POV of synchronization, there should be no need to call
wake_up_process() with the 'kthread_create_lock' being held.

Signed-off-by: Dmitry Adamushko <[e-mail]>
Cc: Nick Piggin <[e-mail]>
Cc: Ingo Molnar <[e-mail]>
Cc: Rusty Russell <[e-mail]>
Cc: "Paul E. McKenney" <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Andy Whitcroft <[e-mail]>
Cc: Oleg Nesterov <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

kernel/kthread.c

···
 
 	spin_lock(&kthread_create_lock);
 	list_add_tail(&create.list, &kthread_create_list);
-	wake_up_process(kthreadd_task);
 	spin_unlock(&kthread_create_lock);
 
+	wake_up_process(kthreadd_task);
 	wait_for_completion(&create.done);
 
 	if (!IS_ERR(create.result)) {