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. 26, 2006
Filed:
May. 25, 2004
Orit Levin-michael, Newton, MA (US);
Josef Ezra, Ashland, MA (US);
Orit Levin-Michael, Newton, MA (US);
Josef Ezra, Ashland, MA (US);
EMC Corporation, Hopkinton, MA (US);
Abstract
A method for estimating the fall through time of a cache includes maintaining local statistics associated with each data cache slot replaced by a processor, reading from a memory global statistics related to each data cache slot replaced by a plurality of processors, calculating new global statistics, and estimating a fall through time of the cache in response to the global statistics at a predetermined rate. When the global statistics are the result of at least a threshold number of data cache slots having been replaced, the new global statistics are calculated by weighting the global statistics by a factor of less than one and adding the weighted global statistics to the local statistics. When the global statistics are not the result of at least a threshold number of data cache slots having been replaced, the new global statistics are calculated by adding a time related to the lapsed time to a global sum value associated with the time stamp difference of the replaced data cache slots. In a multi-processor computer system, each of the processors accesses the global memory to update the global statistics at a different time. The fall through time is estimated continuously at a first predetermined rate and the global statistics are updated at a second predetermined rate that, in one embodiment, is a multiple of the first predetermined rate.