Abstract: A file sharing method and system for a multiprocessor system has an auxiliary storage unit that is shared in use by a plurality of processors each adopting virtual storage management. An auxiliary page table for storing on a page-by-page basis addresses of files contained in the auxiliary storage unit is prepared on a main storage provided for each of the processors. In response to a file map request issued by a program, an address of the file stored in said auxiliary storage unit is stored in the auxiliary page file. When the file is not stored in the main storage, a page exception interruption occurs, in response to which the address of the file stored in the auxiliary page table is referenced to for thereby transferring the file to the main storage from the auxiliary storage unit. The file stored in the auxiliary storage unit is transferred in the state undergoing an exclusion control.

Abstract: In a storage control method for use in a computer system having a main storage, a first external storage, and a second external storage having an access speed higher than that of the first external storage, a check is made for a free area of the second external storage to decide a size of the free area. The size is compared with a predetermined first reference value. If the size is smaller, to prepare a free area having a size not less than the first reference value, the storage contents are transferred from the second external storage to the first external storage. If the free area size is larger than the first reference value, the size is next compared with a predetermined second reference value greater than the first reference value. If the size is larger than the first reference value and smaller than the second reference value, a predetermined amount of the storage contents are transferred from the second external storage to the first external storage.

Abstract: A virtual storage management method in a multi-processor system in which individual processors share an external storage is shown. Data of the virtual storage is stored in the shared external storage, and a page table for managing the virtual storage of each processor is also stored in the shared external storage. By exclusively controlling an access to that page table, the virtual storage can be managed.

Abstract: In a method and apparatus wherein a logical address of a main storage designated by a program is translated into a real address: an address translation table for each of a plurality of address translation sizes is prepared; the logical address designated by the program is fetched; an entry of an address translation table whose address translation size is larger than those of the other address translation tables among the plurality of address translation sizes is first identified based on the fetched logical address; a first information on an address translation size validity included in the first indentified entry is checked; address translation in units of translation size of the address translation table including the first identified entry is performed when the first information indicates valid; when the first information indicates invalid, an entry of an address translation table whose address translation size is next smaller than that of the address translation table including the first identified entry

Abstract: In a memory system having a storage device and a key storage keeping key data controlling an access to the storage device, there is disposed a key address translation structure for obtaining an address of an entry of the key storage based on an address of the storage device to which an access request is issued. As a result, when subdividing the storage device according to the key data setting unit, each subdivided area can be assigned with a variable size and a plurality of sizes are enabled to be specified for the key data setting units at the same time.