Real-Time Systems Symposium 

About: Real-Time Systems Symposium is an academic conference. The conference publishes majorly in the area(s): Scheduling (computing) & Dynamic priority scheduling. Over the lifetime, 1544 publications have been published by the conference receiving 72946 citations.

The rate monotonic scheduling algorithm: exact characterization and average case behavior

Abstract: An exact characterization of the ability of the rate monotonic scheduling algorithm to meet the deadlines of a periodic task set is represented. In addition, a stochastic analysis which gives the probability distribution of the breakdown utilization of randomly generated task sets is presented. It is shown that as the task set size increases, the task computation times become of little importance, and the breakdown utilization converges to a constant determined by the task periods. For uniformly distributed tasks, a breakdown utilization of 88% is a reasonable characterization. A case is shown in which the average-case breakdown utilization reaches the worst-case lower bound of C.L. Liu and J.W. Layland (1973). >

Fixed priority scheduling of periodic task sets with arbitrary deadlines

Abstract: Consideration is given to the problem of fixed priority scheduling of period tasks with arbitrary deadlines. A general criterion for the schedulability of such a task set is given. Worst case bounds are given which generalize the C.L. Liu and J.W. Layland (1973) bound. The results are shown to provide a basis for developing predictable distributed real-time systems. >

Preemptive Scheduling of Multi-criticality Systems with Varying Degrees of Execution Time Assurance

Abstract: This paper is based on a conjecture that the more confidence one needs in a task execution time bound (the less tolerant one is of missed deadlines), the larger and more conservative that bound tends to become in practice. We assume different tasks perform functions having different criticalities and requiring different levels of assurance. We assume a task may have a set of alternative worst-case execution times, each assured to a different level of confidence. This paper presents ways to use this information to obtain more precise schedulability analysis and more efficient preemptive fixed priority scheduling. These methods are evaluated using workloads abstracted from production avionics systems.

Preemptively scheduling hard-real-time sporadic tasks on one processor

Abstract: Consideration is given to the preemptive scheduling of hard-real-time sporadic task systems on one processor. The authors first give necessary and sufficient conditions for a sporadic task system to be feasible (i.e., schedulable). The conditions cannot, in general, be tested efficiently (unless P=NP). They do, however, lead to a feasibility test that runs in efficient pseudo-polynomial time for a very large percentage of sporadic task systems. >

Integrating multimedia applications in hard real-time systems

Abstract: This paper focuses on the problem of providing efficient run-time support to multimedia applications in a real-time system, where two types of tasks can coexist simultaneously: multimedia soft real-time tasks and hard real-time tasks. Hard tasks are guaranteed based on worst case execution times and minimum interarrival times, whereas multimedia and soft tasks are served based on mean parameters. The paper describes a server-based mechanism for scheduling soft and multimedia tasks without jeopardizing the a priori guarantee of hard real-time activities. The performance of the proposed method is compared with that of similar service mechanisms through extensive simulation experiments and several multimedia applications have been implemented on the HARTIK kernel.