Performance monitoring in a NUMA computer

A performance monitor for a computer system that includes an interface, a filter module, and an address mapping module. The interface is suitable for coupling to an interconnect network of the computer system. The interconnect network links a local node of the system with at least one remote node of the system. The interface is configured to extract physical address information from a transaction traversing the interconnect network. The filter module associates the physical address with one of several memory blocks, where each memory block comprises a contiguous portion of the system's physical address space. The address mapping module associates the identified memory block with at least one range of virtual addresses associated with at least one of a plurality of concurrently executing programs and increments each of a set of access counters. The association between the selected memory block and the access counters is facilitated by a pointer field corresponding to the memory block.