Abstract: The method includes initiating a processor request to a cache in a requesting node and broadcasting the processor request to remote nodes when the processor request encounters a local cache miss, performing a directory search of each remote cache to determine a state of a target line's address and an ownership state of a specified address, returning the state of the target line to the requesting node and forming a combined response, and broadcasting the combined response to each remote node. During a fetch operation, when the directory search indicates an IM or a Target Memory node on a remote node, data is sourced from the respective remote cache and forwarded to the requesting node while protecting the data, and during a store operation, the data is sourced from the requesting node and protected while being forwarded to the IM or the Target Memory node after coherency has been established.

Abstract: A method of preventing lockout and stalling conditions in a multi-node system having a plurality of nodes which includes initiating a processor request to a shared level of cache in a requesting node, performing a fabric coherency establishment sequence on the plurality of nodes, issuing a speculative memory fetch request to a memory, detecting a conflict on one of the plurality of nodes and communicating the conflict back to the requesting node within the system, canceling the speculative memory fetch request issued, and repeating the fabric coherency establishment sequence in the system until the point of conflict is resolved, without issuing another speculative memory fetch request. The subsequent memory fetch request is only issued after determining the state of line within the system, after the successful completion of the multi-node fabric coherency establishment sequence.

Abstract: The method includes initiating a processor request to a cache in a requesting node and broadcasting the processor request to remote nodes when the processor request encounters a local cache miss, performing a directory search of each remote cache to determine a state of a target line's address and an ownership slate of a specified address, returning the state of the target line to the requesting node and forming a combined response, and broadcasting the combined response to each remote node. During a fetch operation, when the directory search indicates an IM or a Target Memory node on a remote node, data is sourced from the respective remote cache and forwarded to the requesting node while protecting the data, and during a store operation, the data is sourced from the requesting node and protected while being forwarded to the IM or the Target Memory node after coherency has been established.

Abstract: A method of preventing lockout and stalling conditions in a multi-node system having a plurality of nodes which includes initiating a processor request to a shared level of cache in a requesting node, performing a fabric coherency establishment sequence on the plurality of nodes, issuing a speculative memory fetch request to a memory, detecting a conflict on one of the plurality of nodes and communicating the conflict back to the requesting node within the system, canceling the speculative memory fetch request issued, and repeating the fabric coherency establishment sequence in the system until the point of conflict is resolved, without issuing another speculative memory fetch request. The subsequent memory fetch request is only issued after determining the state of line within the system, after the successful completion of the multi-node fabric coherency establishment sequence.