Advanced Micro Devices, Inc.
USING A BLOOM FILTER TO REDUCE THE NUMBER OF MEMORY ADDRESSEES TRACKED BY A COHERENCE DIRECTORY

Abstract:

An approach for tracking data stored in caches uses a Bloom filter to reduce the number of addresses that need to be tracked by a coherence directory. When a requested address is determined to not be currently tracked by either the coherence directory or the Bloom filter, tracking of the address is initiated in the Bloom filter, but not in the coherence directory. Initiating tracking of the address in the Bloom filter includes setting hash bits in the Bloom filter so that subsequent requests for the address will "hit" the Bloom filter. When a requested address is determined to be tracked by the coherence directory, the Bloom filter is not used to track the address.