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:
Mar. 23, 1993
Filed:
Apr. 05, 1990
Philip G Emma, Danbury, CT (US);
Joshua W Knight, Mohegan Lake, NY (US);
James H Pomerene, Chappaqua, NY (US);
Thomas R Puzak, Ridgefield, CT (US);
Rudolph N Rechtschaffen, Scarsdale, NY (US);
Frank J Sparacio, Sarasota, FL (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A store through cache environment managed exclusively grants exclusivity on a large granularity basis. A cross-invalidate is realized for all changed lines via a single transmission when exclusivity is released. A dynamic table that operates in conjunction with a directory look-aside table (DLAT) determines a number of pages that can be held exclusive simultaneously. For adequate operating speed, the special table must be either fully associative or at least set associative. Alternatively, the table can be incorporated into the DLAT. Each DLAT entry is also extended to include a set of 'resident' bits and a 'valid nonresident' bit. When exclusively is released, the set of local change bits is broadcast to all processors. Upon receipt of such broadcast, the appropriate action is to change the 'valid nonresident' indication to read-only and to clear residence bits whose corresponding local change bit is set.