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:
Dec. 03, 2002
Filed:
May. 28, 1999
Richard L. Frank, Groton, MA (US);
Gopalan Arun, Nashua, NH (US);
Michael J. Cusson, Chelmsford, MA (US);
Daniel E. O'Shaughnessy, Hollis, NH (US);
Oracle Corporation, Redwood Shores, CA (US);
Abstract
A method for maintaining virtual memory consistency in a multi-processor environment comprises allocating a subset of virtual memory to a process, and mapping the subset of virtual memory to a first subset of physical memory. A translator lookaside buffer (TLB) is maintained in each processor, each TLB comprising a plurality of TLB entries. Each TLB entry represents a mapping between a virtual address in the subset of virtual memory and a physical address in the first subset of physical memory. When the subset of virtual memory is to be unmapped, a reference to the first subset of physical memory is placed into a free list, and marked as dirty. When the number of dirty references exceeds a predetermined threshold, the corresponding entries in each processor's TLB are invalidated. Alternatively, all TLB entries can be invalidated. The free list comprises a plurality of free list entries, where each entry comprises a reference to virtual memory which is either unmapped or whose mapping is dirty.