Using cuckoo movement for improved cache coherency

摘要

Example implementations of the present disclosure are directed to handling the eviction of a conflicting cuckoo entry while reducing performance degradation resulting. In example implementations, when an address is replacing another address, the evicted address does not necessarily map to the same places as the new address. Example implementations attempt to conduct a run through of the cache coherent directory with the new entry such that the evicted address can find an empty entry in the directory and fill the empty entry.

主权项

1. A method, comprising:
managing a coherency directory for a cache coherent system, the coherency directory comprising a plurality of entries arranged in a cuckoo hash; for a new entry for the coherency directory causing a replacement of one of the plurality of entries in the coherency directory:
placing the replaced one of the plurality of entries into an eviction buffer; andattempting to reinsert the replaced one of the plurality of entries into a different position within the coherency directory;wherein the attempting to reinsert the replaced one of the plurality of entries comprises:
invoking a clean invalid operation to the coherency directory; for the clean invalid operation finding an empty location in the coherency directory for the replaced one of the plurality of entries, canceling the clean invalid operation and moving the replaced one of the plurality of entries into the empty location;
for the clean invalid operation not finding an empty location in the coherency directory for the replaced one of the plurality of entries, removing one or more of the plurality of entries through a snoop operation triggered by the clean invalid operation.