Application Load Imbalance on Parallel Processors

This paper addresses the issue of dynamic load imbalance in a class of synchronous iterative applications, and develops a model to represent their workload dynamics. Such models of application load dynamics help in more accurate performance prediction and in the design of efficient load balancing algorithms. Our model captures the workload dynamics across iterations, and predicts the workload distribution at any given iteration as the cumulative effect of workload dynamics during the preceding iterations. The model parameters are derived using empirical data from initial runs of the application. The model development is illustrated using data from a parallel N-body simulation application.