We present a runtime solution to self-configuration of systems that are subject to hard realtime constraints. The presented approach builds on an admission control scheme, that verifies the implications of a configuration change on system timing, prior to the actual reconfiguration process. Based on this verification process, the self-configuration finds feasible priority assignments for otherw...

Service time distributions at computer processing units are often nonexponential. Empirical studies show that different programs may have markedly different processing time requirements. When queuing disciplines are first come, first served, preemptive priority or nonpreemptive priority, models reflecting these characteristics are difficult to analyze exactly. Available approximate techniques a...

We present a first constant performance guarantee for preemptive stochastic scheduling to minimize the sum of weighted completion times. For scheduling jobs with release dates on identical parallel machines we derive a policy with a guaranteed performance ratio of 2 which matches the currently best known result for the corresponding deterministic online problem. Our policy applies to the recent...

For lack of optical random access memory, optical fiber delay line (FDL) is currently the only technology to implement optical buffering. Feed-forward and feedback are two types of FDL structures in optical buffering, both have advantages and disadvantages. In this paper, we present a novel architecture for WDM optical packet switches with an effective hybrid FDL buffering that combines the mer...

This paper studies static-priority preemptive scheduling on a multiprocessor using partitioned scheduling. We propose a new scheduling algorithm and prove that if the proposed algorithm is used and if less than 50% of the capacity is requested then all deadlines are met. It is known that for every static-priority multiprocessor scheduling algorithm, there is a task set that misses a deadline al...

We study a first passage time problem for a class of spectrally positive Lévy processes. By considering the special case where the Lévy process is a compound Poisson process with negative drift, we obtain the Laplace-Stieltjes transform of the steady-state waiting time distribution of low-priority customers in a twoclass M/GI/1 queue operating under a dynamic non-preemptive priority discipline....

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...

In this paper, we consider a discrete-time non-preemptive priority queueing model with priority jumps. Two classes, real-time (high priority) and non-real time (low priority), of traffic will be considered with providing jumps from lower priority traffic to the queue of high priority traffic. We derive expressions for the joint probability generating function of the system contents of the high ...