[ 6] rcu_dynticks_inc()+0x3a
[ 5] rcu_momentary_dyntick_idle()+0x2e
[ 4] multi_cpu_stop()+0xf4
[ 3] cpu_stopper_thread()+0x7e
[ 2] smpboot_thread_fn()+0x142
[ 1] kthread()+0x10e
[ 0] ret_from_fork()+0x14