Simulation and visualization tools for link-based parallel architectures

Parallel systems are wellknown solutions to satisfy the demand of computing capabilities, but parallel computer design involves difficult hardware/software tradeoffs. Standard general purpose parallel architectures don't exist, only some particular architectures are used to solve specific problems. In such complex systems the performance measurement is important to evaluate several situations for existing architectures or for systems in designing phase. This performance is highly influenced by factors as interconnection scheme, granularity, computing/communication ratio, algorithm topology and operating system policies. Interaction between these factors is not easy to understand and often unpredictable. Simulation has proved to be useful as a tool for system design and performance evaluation, allowing a simple way to compare different alternatives. In this paper, an integrated simulation environment for the design and evaluation of parallel computing systems is presented. It has been designed for a large-grain data flow programming model, which we call Weighted Behavioral Graph (WBG). This formalism allows the representation of both the static and dynamic properties of the program graph. The simulation environment provides facilities for the program and interconnection graph's specification, as well as the scheduler and router policy's selection. An icon based, multiwindow graphic front end allows for a friendly man-machine interface, thus reducing the model's development cycle. © 1991.