Volume 11, Number 08, June 2021

Hierarchical Scheduling for Real-Time Periodic Tasks in Symmetric Multiprocessing

  Authors

Tom Springer and Peiyi Zhao, Chapman University, USA

  Abstract

In this paper, we present a new hierarchical scheduling framework for periodic tasks in symmetric multiprocessor (SMP) platforms. Partitioned and global scheduling are the two main approaches used by SMP based systems where global scheduling is recommended for overall performance and partitioned scheduling is recommended for hard real-time performance. Our approach combines both the global and partitioned approaches of traditional SMP-based schedulers to provide hard real-time performance guarantees for critical tasks and improved response times for soft real-time tasks. Implemented as part of VxWorks, the results are confirmed using a real-time benchmark application, where response times were improved for soft real-time tasks while still providing hard real-time performance.

  Keywords

Real-time systems, hierarchical scheduling, symmetric multiprocessing, operating systems.