  We study in this paper the impact of communication latency on the classical
Work Stealing load balancing algorithm. Our approach considers existing
performance models and the underlying algorithms. We introduce a latency
parameter in the model and study its overall impact by careful observations of
simulation results. Using this method we are able to derive a new expression of
the expected running time of divisible load applications. This expression
enables us to predict under which conditions a given run will yield acceptable
performance. For instance, we can easily calibrate the maximal number of
processors one should use for a given work platform combination. We also
consider the impact of several algorithmic variants like simultaneous transfers
of work or thresholds for avoiding useless transfers. All our results are
validated through simulation on a wide range of parameters.
