Memory coherence directory supporting remotely sourced requests of nodal scope

A node interface for a processing node of a data processing system including at least three processing nodes coupled by an interconnect fabric, wherein the node interface includes:

• at least one interconnection for a communication link with another processing node of the data processing system;
• at least one interconnection for a communication link with a processing unit in the processing node;
• an address facility indicating which memory blocks are assigned to the processing node;
• a directory indicating if memory blocks assigned to the processing node are cached other than in the processing node;
• and
• logic that, responsive to receipt of a remotely sourced request from said another processing node of the data processing system, said request having a scope of transmission limited to the processing node such that the request is not received by snoopers in others of the at least three processing nodes and said request indicating a target memory block qualified by the address facility as assigned to the processing node, permits the request to proceed with the nodal scope of transmission if the directory does not indicate that the target memory block of the request is cached other than in the processing node and prevents the request from succeeding if the directory indicates that the target memory block of the request is cached other than in the processing node.