Method and Apparatus for History-Based Snooping of Last Level Caches

摘要

A method and apparatus for snooping caches is disclosed. In one embodiment, a system includes a number of processing nodes and a cache shared by each of the processing nodes. The cache is partitioned such that each of the processing nodes utilizes only one assigned partition. If a query by a processing node to its assigned partition of the cache results in a miss, a cache controller may determine whether to snoop other partitions in search of the requested information. The determination may be made based on history of where requested information was obtained from responsive to previous misses in that partition.

主权项

1. A system comprising:
a plurality of processing nodes; a first cache memory, wherein the first cache memory is subdivided into a plurality of partitions, wherein each of the plurality of processing nodes is associated with a corresponding unique one of the plurality of partitions, and wherein each of the plurality of partitions is dedicated to store information for its corresponding ones of the plurality of processing nodes; plurality of history circuits each associated with a unique one of the plurality of partitions of the first cache memory, wherein each of the plurality of history circuits is configured to store history indicating whether requested information from previous queries was found in another one of the plurality of partitions responsive to a miss in its corresponding one of the plurality of partitions; a cache controller configured to, responsive to a miss in a particular one of the plurality of partitions, determine whether to snoop other ones of the plurality of partitions for currently requested information based on the history stored in a corresponding one of the plurality of history circuits.