map_info_walk_t
map_info_walk_t *miw;
miw = mdb_alloc(sizeof (map_info_walk_t), UM_SLEEP);
map_info_walk_t *miw = wsp->walk_data;
map_info_walk_t *miw = wsp->walk_data;
mdb_free(miw, sizeof (map_info_walk_t));