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:
Apr. 30, 2002
Filed:
Sep. 30, 1999
David E. McCracken, San Francisco, CA (US);
Allan James Christie, Fremont, CA (US);
James A. Stuart Fiske, Palo Alto, CA (US);
Silicon Graphics, Inc., Mountianview, CA (US);
Abstract
A memory protection system for shared memory in a multiprocessor computer is provided that comprises a multiprocessor computer ( ) having a plurality of processor regions and a plurality of memory pages ( ). Each processor region includes one or more processors ( ). Each processor ( ) includes a cache ( ), and each memory page ( ) includes one or more cache lines ( ) for coupling to the cache ( ) of processors ( ) within the plurality of processor regions using the memory page ( ). Each memory page ( ) includes a set of protection bits ( ) associated with each processor region in the plurality of processor regions. The set of protection bits ( ) includes an acquire protection bit ( ) for each processor region in the plurality of processor regions. The acquire protection bit ( ) determines whether the associated processor is enabled to perform acquire operations on the memory page ( ). The set of protection bits ( ) also includes a release protection bit ( ) for each processor region in the plurality of processor regions. The release protection ( ) determines whether the associated processor is enabled to perform release operations on the memory page ( ).