#ifdef CONFIG_RWSEM_SPIN_ON_OWNER
  static inline void rwsem_set_owner(struct rw_semaphore *sem)
  {
  	sem->owner = current;
  }
  
  static inline void rwsem_clear_owner(struct rw_semaphore *sem)
  {
  	sem->owner = NULL;
  }
  
  #else
  static inline void rwsem_set_owner(struct rw_semaphore *sem)
  {
  }
  
  static inline void rwsem_clear_owner(struct rw_semaphore *sem)
  {
  }
  #endif