Global Fixed Priority Scheduling with Preemption Threshold: Schedulability Analysis and Stack Size Minimization

Abstract

Memory is a limited resource in cost-sensitive, resource-constrained embedded applications. Preemption Threshold Scheduling (PTS) is a well-known technique for reducing the system stack size requirement. We consider Global Fixed Priority Scheduling with Preemption Threshold (gFPPT), as integration of PTS with global Fixed-Priority scheduling on a homogeneous multiprocessor platform, and formulate the optimization problem of minimizing the system stack size requirement while guaranteeing schedulability. We present schedulability analysis, optimization algorithms for priority and preemption threshold assignment, and an ILP formulation for computing system stack size requirement. Performance evaluation shows that the system stack size requirement can be reduced significantly with gFPPT compared to preemptive scheduling.