Timed Colored Petri Net Models of Distributed Memory Multithreaded Multiprocessors

Distributed{memory multithreaded multiprocessors are composed of a number of (multithreaded) processors, each with its memory, and an interconnecting network. The long memory latencies and synchronization delays are tolerated by context switching, i.e., by suspending the current thread and switching the processor to another `ready' thread provided such a thread is available. Because of very simple representation of concurrency and synchronization, timed Petri net models seem to be well suited for modeling and evaluation of such systems. Colors are used to represent the progress of remote memory access requests in the interconnecting network as well as to fold the models of individual processors. This paper describes timed colored Petri net models of several multithreaded multiprocessor architectures, and presents some performance characteristics obtained by evaluation of these models.