Patents by Inventor Yoshitaka Ohfusa

Yoshitaka Ohfusa has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 5619691
    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.
    Type: Grant
    Filed: January 4, 1995
    Date of Patent: April 8, 1997
    Assignees: Hitachi, Ltd., Hitachi Software Engineering Co., Ltd.
    Inventors: Hisashi Katada, Toshiaki Arai, Yasufumi Yoshizawa, Yoshitaka Ohfusa, Masayuki Kami
  • Patent number: 5446841
    Abstract: An information processing system comprises: plural processors; a shared memory connected to the plurality of processors for enabling communication between the processors; a unit disposed in the shared memory for storing information for specifying a processor connected thereto; and a unit for checking, when a first processor communicates with a second processor, whether or not the first and second processors are connected to the shared memory for direct access thereto by referring to the information storing means.
    Type: Grant
    Filed: June 15, 1992
    Date of Patent: August 29, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Masahiro Kitano, Yoshitaka Ohfusa, Katsuya Kohda, Keiichi Sasaki, Hiroyuki Okura, Katsumi Takeda
  • Patent number: 5404478
    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.
    Type: Grant
    Filed: April 14, 1994
    Date of Patent: April 4, 1995
    Assignee: Hitachi, Ltd.
    Inventors: Toshiaki Arai, Tomonori Miyashita, Yoshitaka Ohfusa, Hisashi Katada
  • Patent number: 5193172
    Abstract: An information processing system managing a virtual memory by using a real memory system comprising a single or a plurality of processors which, when a real page allocation request occurs in a processor or task keeping the use priority that the real pages of a group among the divided groups of the real pages of said memory can be used in a priority basis, allocated the real pages belonging to said group for which said processor or task keeps the use priority to said processor or task in a priority basis so as to decrease the cache cancel rate and the mapping fault occurrence rate and to allow for smoothing and high speed access of the main memory.
    Type: Grant
    Filed: January 22, 1990
    Date of Patent: March 9, 1993
    Assignee: Hitachi, Ltd.
    Inventors: Toshiaki Arai, Yoshitaka Ohfusa, Hirohumi Nagasuka, Yasufumi Yoshizawa
  • Patent number: 4903234
    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.
    Type: Grant
    Filed: May 20, 1988
    Date of Patent: February 20, 1990
    Assignee: Hitachi, Ltd.
    Inventors: Taketoshi Sakuraba, Hisashi Katada, Yoshitaka Ohfusa, Yasufumi Yoshizawa, Toshiaki Arai, Hiroo Miyadera