extern void space_map_create(space_map_t *sm, uint64_t start, uint64_t size,
uint8_t shift, kmutex_t *lp);
extern void space_map_destroy(space_map_t *sm);
extern void space_map_create(space_map_t *sm, uint64_t start, uint64_t size,
uint8_t shift, kmutex_t *lp);
extern void space_map_destroy(space_map_t *sm);