Abstract: A call-graph profile is created by constructing a finite state machine during execution of a program to be analyzed. Each state in the state machine corresponds to an execution context, ie. the set of subroutines that are active in the program at a particular time, together with information about the subroutines that precede and follow their most recent activation on the program's stack. Each transition between states represents a change in execution context taking place on a subroutine call. Each state is represented by a dynamically-allocated record containing a counter that stores the number of times the state has been entered, a counter storing the number of self-transitions made from the state to itself, a timer that stores the total time spent in the state, and data that records the set of subroutines that are active in the execution context.