Patent US 5,355,487

The invention disclosed herein is a system and method for comprehensive, non-invasive profiling of a processor whereby feedback is provided to a programmer of the execution dynamics of a program. In a preferred embodiment a partial real-time reduction is provided of selected trace events employing the environment's trace facility, and a post-processing function is then performed. A trace hook is provided in the environment's periodic clock routine which captures the address to be returned to following this timer's interrupt, and further captures the address of the caller of the routine represented by the first address. The frequency of occurrences of the first address is collected and correlated to various virtual address spaces and corresponding subroutine offsets within those virtual address spaces. By employing the assembly and source code listing of programs, the address frequencies are then correlated back to specific instructions, and from information in the assembly listing accumulated time is further correlated against specific lines of source code. A profile is generated indicating the amount of time spent by the processor in various processes, kernel, shared library, and user spaces, and subroutines correlated to the lines of source code for negligible additional processor run time.