Live Webcast 15th Annual Charm++ Workshop

Simulation studies are quite useful for performance prediction on new architectures and for systematic analysis of performance perturbations caused by variations in the machine parameters, such as communication latencies. Trace-driven simulation is necessary to avoid large computational costs over multiple simulation runs. However, trace-driven simulation of nondeterministic programs has turned out to be almost impossible. Simulation of message-driven programs is particularly challenging in this context because they are inherently nondeterministic. Yet message-driven execution is a very effective technique for enhancing performance, particularly in the presence of large or unpredictable communication latencies. We present a methodology for simulating message-driven programs. The information that is necessary to carry out such simulations is identified, and a method for extracting such information from program executions is described.