A system, method, and computer program for analyzing code execution and software performance characteristics are disclosed. Samples of executing code may be taken based on any of a number of various triggers. For example, samples may be triggered based on function calls, such as malloc calls. Alternatively, samples may be triggered based on occurrence of a specified event. Code execution is graphically displayed such that certain patterns may be easily identified. Multiple redundant function calls and areas of code having excessively deep function calls can be readily spotted. Such areas represent opportunities for performance optimization.