Preemptive LCFS Scheduling in Hard Real-Time Applications

Blieberger, J. and U . Schmid, Preemptive LCFS scheduling in hard real-time applications, Performance Evaluation 15 (1992) 203-215 . We investigate the real-time behaviour of a (discrete time) single server system with preemptive LCFS task scheduling . The main result deals with the probability distribution of a random variable SRD(T), which describes the time the system operates without violating a fixed task service time deadline T . The tree approach, used for the derivation of our results, is also suitable for revisiting problems in queueing theory . Relying on a simple general probability model, asymptotic formulas concerning all moments of SRD(T) are determined ; for instance, the expectation of SRD(T) is proved to grow exponentially in T, i .e ., E[SRD(T)] CpTT3/2 for some p > 1 .