US Patent 7296121 Reducing probe traffic in multiprocessor systems

A computer system having a plurality of processing nodes interconnected by a first point-to-point architecture is described. Each processing node has a cache memory associated therewith. A probe filtering unit is operable to receive probes corresponding to memory lines from the processing nodes and to transmit the probes only to selected ones of the processing nodes with reference to probe filtering information. The probe filtering information is representative of states associated with selected ones of the cache memories.