ct_rcu_watching
trace_rcu_watching(TPS("End"), ct_nesting(), 0, ct_rcu_watching());
trace_rcu_watching(TPS("Start"), ct_nesting(), 1, ct_rcu_watching());
ct_rcu_watching());
trace_rcu_watching(TPS("Endirq"), ct_nmi_nesting(), 0, ct_rcu_watching());
ct_nmi_nesting() + incby, ct_rcu_watching());
if (ct_rcu_watching() & CT_RCU_WATCHING)