COHERENCY PROBE WITH LINK OR DOMAIN INDICATOR

A processor includes a set of processing modules, each of the processing modules including a cache and a coherency manager that keeps track of the memory addresses of data stored at the caches of other processing modules. In response to its local cache requesting access to a particular memory address or other triggering event, the coherency manager generates a coherency probe. In the event that the generated coherency probe is targeted to multiple processing modules, the coherency manager includes a set of multicast bits indicating the processing modules whose caches include copies of the data targeted by the multicast probe. A transport switch that connects the processing module to the fabric communicates the coherency probe only to subset of processing modules indicated by the multicast bits.