rcu_dereference_sched_domain
sd = rcu_dereference_sched_domain(this_rq->sd);
sd = rcu_dereference_sched_domain(cpu_rq(cpu)->sd);
for (__sd = rcu_dereference_sched_domain(cpu_rq(cpu)->sd); \
sdp = rcu_dereference_sched_domain(per_cpu(sd_llc, cpu));
sd = rcu_dereference_sched_domain(cpu_rq(i)->sd);