lru_gen_sum_memcg_stats_for_gen
long idle_pages = lru_gen_sum_memcg_stats_for_gen(lru_gen_last_gen,
long lru_gen_sum_memcg_stats_for_gen(int gen, const struct memcg_stats *stats);
return lru_gen_sum_memcg_stats_for_gen(-1, stats);
if (lru_gen_sum_memcg_stats_for_gen(gen, stats) > pages)