Validating timing constraints of dependent jobs with variable execution times in distributed real-time systems

Abstract

In multiprocessor and distributed real-time systems, scheduling jobs dynamically on processors can be used to achieve better performance. However, analytical and efficient validation methods for determining whether all the timing constraints are met do not yet exist for systems using modern dynamic scheduling strategies, and exhaustive methods are often infeasible or unreliable since the execution time and release time of each job may vary. In this paper, we present several upper bounds and efficient algorithms for computing the worst-case completion times of dependent jobs in dynamic systems where jobs are dispatched and scheduled on available processors in a priority-driven manner. The bounds and algorithms consider arbitrary release times and variable execution times. We present conditions under which dependent jobs execute in a predictable manner. © Springer-Verlag Berlin Heidelberg 2002.