| 摘要 |
A method and apparatus for implementing a snoop filter unit associated with a single processor in a multiprocessor system. The snoop filter unit has a plurality of ports, each port receiving snoop requests from exactly one dedicated source. Associated with each port is a snoop cache filter that processes each snoop cache request and records addresses of the most recent snoop requests for exactly one source. The snoop cache filter uses vector encoding to record the occurrence of snoop requests for a sequence of consecutive cache lines. All addresses of snoop requests are added to the snoop cache unless a received snoop cache request matches an entry present in the associated snoop cache, in which case the snoop request is discarded. Otherwise, the associated snoop cache request is enqueued for forwarding to the single processor. Information from all snoop cache filters assigned to all ports in the snoop filter unit are removed in the case that data corresponding to any one of the memory addresses contained in snoop cache filter is loaded in the cache hierarchy of the processor the snoop cache filter is assigned to.
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