Preemptive Task Scheduling for Distributed Systems

Task scheduling in a preemptive runtime environment has potential advantages over the non-preemptive case such as better processor utilization and more flexibility when scheduling tasks. Furthermore, preemptive approaches may need less runtime support (e.g. no task ordering required). In contrast to the non-preemptive case, preemptive task scheduling in a distributed system has not received much attention. In this paper we present a low-cost algorithm, called the Preemptive Task Scheduling algorithm (PTS), which is intended for compile-time scheduling of coarse-grain problems in a preemptive distributed-memory system. We show that PTS combines the low-cost of the algorithms for the non-preemptive case with a simpler runtime support, while the output performance is still at a level comparable to the non-preemptive schedules.