An operating system monitoring tool has two components: a hyperkernel that augments the operating system of a target multiprocessing system; and a graphical front end for implementing the user interface. The hyperkernel component is annexed to the operating system by: intercepting all interrupts and redirecting them from the operating system to the hyperkernel; and substituting a jump to the hyperkernel for each point in the operating system that returns back to the application code. Associated with the hyperkernel are buffers, located on the respective processors, that accumulate information pertaining to calls to the operating system. On demand, or when the buffers fill, the accumulated information is relayed to the graphical front end for filtering, manipulation, and display.