lruvec_lru_size
unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone_idx);
lruvec_size = lruvec_lru_size(lruvec, lru, sc->reclaim_idx);
pages += lruvec_lru_size(lruvec, i, MAX_NR_ZONES - 1);