2013 IEEE 19th Real-Time and Embedded Technology and Applications Symposium (RTAS) (2013)
Philadelphia, PA, USA USA
Apr. 9, 2013 to Apr. 11, 2013
L. T. X. Phan , Dept. of Comput. & Inf. Sci., Univ. of Pennsylvania, Philadelphia, PA, USA
Insup Lee , Dept. of Comput. & Inf. Sci., Univ. of Pennsylvania, Philadelphia, PA, USA
In this paper, we introduce a technique for improving the schedulability of real-time embedded systems with fixed-priority scheduling. Our technique uses shapers to reduce the resource interference between higher-priority and lower-priority tasks, and thus enables more lower-priority tasks to be scheduled. We present a closed-form solution for the optimal greedy shaper for periodic tasks with jitter, as well as a schedulability condition for tasks in the presence of shapers. We also discuss two applications of greedy shapers: In compositional scheduling frameworks, shapers can help optimize the resource interfaces of real-time components, and in mixed-criticality systems, they can reduce deadline misses of low-criticality tasks while preserving schedulability of high-criticality tasks, even with lower priorities. We demonstrate the utility of our technique through an evaluation based on randomly generated workloads.
Jitter, Interference, Delays, Time factors, Real-time systems, Servers, Embedded systems
L. T. X. Phan, Insup Lee, "Improving schedulability of fixed-priority real-time systems using shapers", 2013 IEEE 19th Real-Time and Embedded Technology and Applications Symposium (RTAS), vol. 00, no. , pp. 217-226, 2013, doi:10.1109/RTAS.2013.6531094