1. A processing unit for a multiprocessor data processing system, said processing unit comprising: a processor core; and a cache hierarchy coupled to the processor core to provide low latency data access, the cache hierarchy including an upper level cache coupled to the processor core and a lower level victim cache coupled to the upper level cache, each of the upper level cache and the lower level victim cache including a respective cache directory and a respective data array, wherein responsive to a prefetch request of the processor core that misses in the upper level cache, the lower level victim cache determines whether the prefetch request misses in the directory of the lower level victim cache and, if so, allocates a state machine in the lower level victim cache that services the prefetch request by issuing the prefetch request to at least one other processing unit of the multiprocessor data processing system.