unbound_pwq_slot
struct pool_workqueue __rcu **slot = unbound_pwq_slot(wq, cpu);
RCU_INIT_POINTER(*unbound_pwq_slot(wq, cpu), NULL);
RCU_INIT_POINTER(*unbound_pwq_slot(wq, -1), NULL);
return rcu_dereference_check(*unbound_pwq_slot(wq, cpu),