The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 20, 2005
Filed:
Aug. 20, 2002
Kenta Ninose, Yokohama, JP;
Hirofumi Nagasuka, Sagamhara, JP;
Masahiro Kiyoi, Kawasaki, JP;
Katsuhisa Miyata, Yokohama, JP;
Kenta Ninose, Yokohama, JP;
Hirofumi Nagasuka, Sagamhara, JP;
Masahiro Kiyoi, Kawasaki, JP;
Katsuhisa Miyata, Yokohama, JP;
Hitachi, Ltd, Tokyo, JP;
Abstract
In a computer system with a plurality of levels of cache storage, a cache control method prevents data duplication among the levels of cache storage to increase cache storage utilization. A high-level cache staging unit stages reads data from a disk unit, stages the data to a high-level cache, and instructs to destage the data, which has been read, from a low-level cache. A high-level cache destaging unit writes data to be destaged to the disk unit, instructs to stage the data, which has been written, to the low-level cache, and destages the data from the high-level cache. A low-level cache staging unit stages a data, which is written by the high-level cache destaging unit, to the low-level cache. A low-level cache destaging unit destages a data, which is instructed by the high-level cache staging unit, from the low-level cache.