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:
Aug. 29, 2000
Filed:
Sep. 19, 1997
Curt F Schimmel, San Ramon, CA (US);
Narayanan Ganapathy, San Jose, CA (US);
Bhanuprakash Subramanya, San Jose, CA (US);
Luis Stevens, Milipitas, CA (US);
Silicon Graphics, Inc., Mountain View, CA (US);
Abstract
A system, method and computer program product for reverse mapping a page of memory to one or more data structure references, such as page table entries, that reference the page of memory. A number m of fields of a page frame data structure are reserved for storing reverse mapping data for a page of memory. Each reserved field can store a reverse map entry for pointing to a data structure reference, such as a page table entry, that references the page of memory that is represented by the page frame data structure. Where a number n of references to the page of memory is greater than the number m of reserved fields, a reverse map table is generated for storing additional reverse map entries. When a reverse map table is generated, one of the reverse map entries in one of the reserved fields of the page frame data structure is moved to the reverse map table. A pointer to the reverse map table is placed in the now-vacant reserved field. Indexes in the page table entries are used to identify and remove the reverse map entries when a page table is deallocated. Reverse map tables can be generated as needed and can be dynamically sized to accommodate any number of reverse map entries.