Novel Response-Time Bounds of Typed DAG Tasks on Heterogeneous Multicores

In recent years, extensive research has been carried out on real-time typed scheduling and analysis of parallel tasks represented as directed acyclic graphs (DAGs) executed on heterogeneous multicores. Although previous studies have examined the schedulability of typed DAG tasks, they still encounter pessimism caused by interference from other tasks. In this article, we explore the worst case response time (WCRT) analysis of typed scheduling for DAG tasks under global scheduling. Here, each vertex in a typed DAG task experiences interference from within itself as well as from higher priority tasks. First, we propose an efficient method to bound the WCRT of typed DAG tasks based on the state-of-the-art parallel task analysis approach. Then, we discover a technique to mitigate the pessimism caused by other tasks, albeit in a nonoptimal manner. Finally, we conduct experiments using randomly generated typed DAG tasks to evaluate the performance of our proposed methods. The results indicate that our proposed approach can yield less pessimistic WCRT under global scheduling.