METHOD TO MINIMIZE THE ENTRY / EXIT ACCESS OPERATIONS IN A DATA PROCESSING SYSTEM, METHOD TO BE USED IN A DATA PROCESSING SYSTEM, METHOD TO GET DATA ACCESS, METHOD TO INCREASE PHYSICAL MEMORY, METHOD TO SHARE DATA METHOD TO REDUCE MESSAGE TRAFFIC

摘要

A method for minimising I/O mechanical assess operations on secondary storage devices in a data processing system having a plurality of processor units interconnected in a cluster configuration to permit each processor unit to request and obtain data that is resident only on a secondary storage device of one processor unit. The method involves the steps of maintaining at each processor unit information about each copy of data that has been sent from the unit to another unit to permit a second request to the unit to be serviced by transferring a copy of the data from the main memory which is storing the data to the requesting unit rather than servicing the request with a relatively slow I/O accessing operation to a secondary storage device.