lru_add
bool is_lru_add = (move_fn == lru_add);
fbatch = this_cpu_ptr(&cpu_fbatches.lru_add);
struct folio_batch lru_add;
folio_batch_add_and_move(folio, lru_add);
struct folio_batch *fbatch = &fbatches->lru_add;
folio_batch_move_lru(fbatch, lru_add);
return folio_batch_count(&fbatches->lru_add) ||