RCU_KTHREAD_RUNNING
if ((in_serving_softirq() || rdp->rcu_cpu_kthread_status == RCU_KTHREAD_RUNNING) &&
if (rdp->rcu_cpu_kthread_status == RCU_KTHREAD_RUNNING &&
*statusp = RCU_KTHREAD_RUNNING;
WRITE_ONCE(rnp->boost_kthread_status, RCU_KTHREAD_RUNNING);