Apple Inc.

Tom Greenshtein

Ilya Granovsky

Sandeep Kumar Gupta

Vivek Venkatraman

Amanvir Singh Sidana

An apparatus includes a plurality of coherent agents, and a coherence directory that includes directory ways for storing coherency information. The coherence directory may be configured to determine that a cache block that is not currently cached among the coherent agents, is stored in a first coherent agent. The coherence directory may be further configured to, in response to this determination, create a particular entry in a selected one of the directory ways. The coherence directory may also be configured to send, to the first coherent agent, an indicator identifying a directory way that includes the entry. In response to a second coherent agent caching the cache block, the coherence directory may update the entry to include the second coherent agent. The first and second coherent agents may be configured to receive copies of the indicator, and to store their copy in locations associated with the cache block.

Coherence directory way tracking in coherent agents

An apparatus includes a cache memory circuit configured to store a cache lines, and a cache controller circuit. The cache controller circuit is configured to receive a read request to an address associated with a portion of a cache line. In response to an indication that the portion of the cache line currently has at least a first sub-portion that is invalid and at least a second sub-portion that is modified relative to a version in a memory, the cache controller circuit is further configured to fetch values corresponding to the address from the memory, to generate an updated version of the portion of the cache line by using the fetched values to update the first sub-portion, but not the second sub-portion, of the portion of the cache line, and to generate a response to the read request that includes the updated version of the portion of the cache line.

Growing community of inventors

Givaat Nesher, Israel

Tom Greenshtein