In the context of Fixed-Priority Scheduling in Real-Time Systems, we investigate scheduling mechanisms for supporting systems where, in addition to timing constraints, their performance with respect to additional QoS requirements must be improved. This type of situation may occur when the worst-case resource requirements of all or some running tasks cannot be simultaneously met due to task cont...

In this paper we present a method for creating scheduling heuristics for parallel proportional machine scheduling environment and arbitrary performance criteria. Genetic programming is used to synthesize the priority function which, coupled with an appropriate metaalgorithm for a given environment, forms the priority scheduling heuristic. We show that the procedures derived in this way can perf...

It is common nowadays to architect and design scaled-out systems with off-the-shelf computing components operated and managed by off-the-shelf open-source tools. While web services represent the critical set of services offered at scale, big data analytics is emerging as a preferred service to be colocated with cloud web services at a lower priority raising the need for off-the-shelf priority s...

Some CPU scheduling algorithms such as First-Come-First-Serve (FCFS), Shortest Job First (SJF), Priority, Round Robin (R-R), Multilevel Queue(MQ) and Multilevel Feedback Queue (MFQ has been elaborated and assessed on the basic CPU scheduling objectives i.e.; average waiting(AWT), average turnaround (ATT)and average response time(ART), average CPU utilization (AU)and average throughput(AT). Thes...

In recent years, fixed priority real-time scheduling has made significant advances. These advances have been applied primarily to CPU scheduling. While CPU scheduling is an important aspect of real-time designs, other shared system resources require the same attention in order for a system to transfer real-time traffic. This paper addresses one such resource, the system bus, and presents a meth...

We present a case study in formal specification and toolassisted verification of real-time schedulers, based on the priority ceiling protocol. Starting from operational specifications of the protocol, we obtain rigorous proofs of both synchronization and timing properties, and we derive a schedulability result for sporadic tasks.

Contemporary networks accommodate handling of multiple priorities, aiming to provide suitable QoS levels to different traffic classes. In the presence of multiple priorities, a scheduling algorithm is employed to select each time the next packet to transmit over the data link. Class-based Weighted Fair Queuing (CBWFQ) scheduling and its variations, is widely used as a scheduling technique, sinc...

This presentation is a tutorial given as a survey of the basic problems arising in real-time schedulability analysis on uniprocessor systems. It mainly focuses on on-line scheduling policies (fixed priority policies FPP, and dynamic priority scheduling) on a preemptive scheduling scheme, and insists on the basic concepts of busy period and processor demand. This tutorial is an extract of a lect...

Admission control schemes and scheduling algorithms are designed to offer QoS services in 802.16/802.16e networks and a number of studies have investigated these issues. But the channel condition and priority of traffic classes are very rarely considered in the existing scheduling algorithms. Although a number of energy saving mechanisms have been proposed for the IEEE 802.16e, to minimize the ...