Response Time Upper Bounds for Fixed Priority Real-Time Systems

This paper derives closed form upper bounds on the response times of tasks in fixed priority real-time systems. These bounds are valid for tasks with arbitrary deadlines, release jitter, and blocking. Response time upper bounds are given for tasks that are scheduled pre-emptively, cooperatively with intervals where pre-emption is deferred, and non-preemptively. The set of upper bounds for n tasks can be computed in O(n) time, providing a linear-time sufficient schedulability test, applicable to complex commercial real-time systems.