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Efficient transient overload tests for real-time systems

  • Guillem Bernat
  • Alan Burns
  • Albert Llamosí
Conference paper
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1245)

Abstract

Timing requirements of real-time systems are usually specified in terms of deadlines which are often classified as being either hard, firm or soft. A hard task must always meet its deadline while a soft or firm one can occasionally miss them. When a task may miss a deadline, traditional scheduling tests do not provide information on the number of deadlines the task may miss. It may just miss a single deadline or may not meet a deadline at all. In this paper we introduce the any n in m and row n in m temporal constraints to model the transient overload a task may suffer. They express that in m consecutive invocations there are at least n deadlines met in any order or in a row. With these temporal constraints we can capture both hard, firm and soft requirements. We present a worst case response time based formulation to compute whether a given set of real-time tasks scheduled under fixed priority meets its n in m temporal constraints.

Keywords

Real-time systems transient overload schedulability analysis 

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Copyright information

© Springer-Verlag Berlin Heidelberg 1997

Authors and Affiliations

  • Guillem Bernat
    • 1
  • Alan Burns
    • 2
  • Albert Llamosí
    • 3
  1. 1.Dept. Matemàtiques i InformàticaUniv. de les Illes BalearsSpain
  2. 2.Dept. Computer ScienceUniv. of YorkEngland
  3. 3.Dept. Enginyeria InformáticaUniv. Rovira i VirgiliTarragonaSpain

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