ct_nesting
ct_nesting() == 0);
if (ct_nesting() != 1) {
trace_rcu_watching(TPS("End"), ct_nesting(), 0, ct_rcu_watching());
oldval = ct_nesting();
trace_rcu_watching(TPS("Start"), ct_nesting(), 1, ct_rcu_watching());
RCU_LOCKDEP_WARN(ct_nesting() < 0,
RCU_LOCKDEP_WARN(ct_nesting() <= 0,