fib_nh_upper_bound
nh_upper_bound = atomic_read(&nexthop_nh->fib_nh_upper_bound);
atomic_set(&nexthop_nh->fib_nh_upper_bound, upper_bound);
if (hash <= atomic_read(&first->fib6_nh->fib_nh_upper_bound)) {
atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);