* - we could be preempted if tree preempt rcu is enabled, so
* it is unsafe to use thread->cpu.
* THREAD_NOTIFY_EXIT
- * - the thread (v) will be running on the local CPU, so
- * v === current_thread_info()
- * - thread->cpu is the local CPU number at the time it is accessed,
- * but may change at any time.
* - we could be preempted if tree preempt rcu is enabled, so
* it is unsafe to use thread->cpu.
*/