Data processing system, method and interconnect fabric having a flow governor

A data processing system, comprising:

• a plurality of point-to-point communication links;
• a plurality of processing units including a remote hub and a plurality of local hubs, wherein said remote hub includes a shared resource, and wherein each of said plurality of local hubs is coupled to said remote hub by a respective one of said plurality of point-to-point communication links;
• wherein each of said plurality of local hubs includes a queue structure that queues requests for access to memory blocks for transmission on a respective one of said point-to-point communication links to said shared resource in said remote hub;
• and
• wherein each of said queue structures transmits requests to said remote hub utilizing only a fractional portion of a bandwidth of its respective point-to-point communication link determined by an allocation policy based at least in part upon a number of said plurality of local hubs and a number of processing units represented by each of said plurality of local hubs, such that requests transmitted by all of said plurality of local hubs do not overrun said shared resource.