Cyclic executives are used to schedule safety-critical real-time systems because of their determinism, simplicity, and efficiency. One major challenge of the cyclic executive model is to produce the cyclic scheduling timetable. This problem is related to the bin-packing problem and is NP-Hard in the strong sense. Unnecessary context switches within the scheduling table can introduce significant...

Context switching times are a major source of overhead in medium to fine grain process scheduling. We compared three different context switching techniques for non-preemptive scheduling in context of hardware/software codesign, and found major differences in performance and code size efficiency.

This paper reports on our on going empirical evalu ation of a two tiered resource allocation scheme assum ing independent jobs that is jobs have no precedence constraints The rst tier extends the temporal density approach load balancing within a time interval while the second tier uses variations of the Earliest Deadline First EDF approach to schedule jobs at a site However job scheduling at si...

This paper reports on our on going empirical evalu ation of a two tiered resource allocation scheme assum ing independent jobs that is jobs have no precedence constraints The rst tier extends the temporal density approach load balancing within a time interval while the second tier uses variations of the Earliest Deadline First EDF approach to schedule jobs at a site However job scheduling at si...

In this work we study the problem of scheduling tasks with dependencies in multiprocessor architectures where processors have different speeds. We present the preemptive algorithm “Save-Energy” that given a schedule of tasks it post processes it to improve the energy efficiency without any deterioration of the makespan. In terms of time efficiency, we show that preemptive scheduling in an asymm...

The embedded systems work on real time operating systems (ERTOS). There are many CPU scheduling policies in general operating systems out of which ERTOS most commonly follow the priority and round robin scheduling. The aim of this research work is to evaluate performance of these scheduling policies. Simulation is adopted as tool to find the best policy that can be implemented to boost the perf...

In many industrial systems, design complexity is partly reduced by the use of non-preemptive message passing or execution. Doing so, context switch overheads are diminished and resource sharing mechanisms are simplified. However, in a mixedcriticality system, long blocking time caused by non-preemptive execution of a task which has lower priority than some other high criticality (HC) tasks migh...

The analysis of link-based global scheduling presented in [1, 2] rests on the assumptions that (i) schedulability is established using a global schedulability test assuming fully preemptive, independent tasks,1 and that (ii) any additional delays incurred due to non-preemptive sections are accounted for by inflating the worst-case execution parameter of each task prior to applying the test. We ...

This paper treats the problem of managing personal tasks, through an adaptation of the Squeaky Wheel Optimization (SWO) framework, enhanced with powerful heuristics and full constraint propagation. The problem involves preemptive and non-preemptive tasks, with extra constraints imposed on the sizes of and the distances between the parts of each preemptive task. Travelling times are imposed by t...