Studying the Effect of Schedule Preemption on Dynamic Task Graph Scheduling
Mohammadali Khodabandehlou, Jared Coleman, Niranjan Suri, Bhaskar Krishnamachari
TL;DR
Dynamic online scheduling of arriving task graphs on heterogeneous networks is NP-hard; the paper introduces Last-K Preemption to balance adaptability and stability in online DAG scheduling. It formalizes the problem, defines three scheduling paradigms (preemptive, non-preemptive, partially preemptive), and evaluates them across synthetic, RIoTBench, WFCommons, and adversarial workloads. The results show that moderate preemption achieves most of the makespan and utilization gains of full preemption while preserving fairness and lowering runtime overhead, making it practical for IoT/edge settings.
Abstract
Dynamic scheduling of task graphs is often addressed without revisiting prior task allocations, with a primary focus on minimizing makespan. We study controlled schedule preemption, introducing the Last-K Preemption model, which selectively reschedules recent task graphs while preserving earlier allocations. Using synthetic, RIoTBench, WFCommons, and adversarial workloads, we compare preemptive, non-preemptive, and partial-preemptive strategies across makespan, fairness, utilization, and runtime. Results show moderate preemption can match most makespan and utilization gains of full preemption while maintaining fairness and low overhead.
