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Cross-Interrogate Line Buffers

IP.com Disclosure Number: IPCOM000042742D
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04

Publishing Venue

IBM

Related People

Authors:
Rechtschaffen, RN So, K [+details]

Abstract

A major source of multiprocessor degradation is the cross-interrogation of one processor's cache by the other. The following reduces the penalty for a cross-interrogation. Analysis has shown that a technique based on the least recently used (LRU) status of cache lines subject to cross-interrogation identifies these lines as the subject of re-cross-interrogation by the original processor. The penalty experienced by a processor whose line is cross-interrogated can be reduced if the line can merely be invalidated and a current copy is provided by the proposed cross-interrogate (XI) line buffer. Fig. 1 shows a 2-way multiprocessor (MP) which maintains XI buffers for a subset of cache lines.