| 摘要 |
PURPOSE:To decrease the load on a central processing unit by providing plural control blocks for input/output start queue, and controlling them respectively by the central processing unit and a channel controller independently. CONSTITUTION:A first queue control block 15 in which a start request is queued by the central processing unit 10 and dequeued by the channel controller 12, is provided, and a second queue control block 17 in which the start request dequeue by the control block 15 is queued by the controller 12 at a time when a route leading to an input/output device 13 is busy, is provided. Also, at the time of queuing the start request to the first queue block 15, the central processing unit decides whether or not to start the controller 12. As a result, the competition between the central processing unit 10 and the channel controller 12 can be reduced, and channel controller starting overheads also can be reduced. |
