Skip to main content
SpringerLink
Log in

EDZL scheduling analysis

  • Published:
Real-Time Systems Aims and scope Submit manuscript

Abstract

A schedulability test is derived for the global Earliest Deadline Zero Laxity (EDZL) scheduling algorithm on a platform with multiple identical processors. The test is sufficient, but not necessary, to guarantee that a system of independent sporadic tasks with arbitrary deadlines will be successfully scheduled, with no missed deadlines, by the multiprocessor EDZL algorithm. Global EDZL is known to be at least as effective as global Earliest-Deadline-First (EDF) in scheduling task sets to meet deadlines. It is shown, by testing on large numbers of pseudo-randomly generated task sets, that the combination of EDZL and the new schedulability test is able to guarantee that far more task sets meet deadlines than the combination of EDF and known EDF schedulability tests.

In the second part of the paper, an improved version of the EDZL-schedulability test is presented. This new algorithm is able to efficiently exploit information on the slack values of interfering tasks, to iteratively refine the estimation of the interference a task can be subjected to. This iterative algorithm is shown to have better performance than the initial test, in terms of schedulable task sets detected.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Baker TP (2003) Multiprocessor EDF and deadline monotonic schedulability analysis. In: Proc of the 24th IEEE real-time systems symposium, Cancun, Mexico, pp 120–129

  • Baker TP (2006) A comparison of global and partitioned EDF schedulability tests for multiprocessors. In: International conf on real-time and network systems, Poitiers, France, pp 119–127

  • Baker TP, Cirinei M (2006) A necessary and sometimes sufficient condition for the feasibility of sets of sporadic hard-deadline tasks. In: Proc of the 27th IEEE real-time systems symposium, Rio de Janeiro, Brazil

  • Baker TP, Cirinei M (2007) Brute-force determination of multiprocessor schedulability for sets of sporadic hard-deadline tasks. In: Principles of distributed systems, 11th int conf, OPODIS 2007, Guadeloupe, French West Indies. Springer, Berlin, pp 62–75

    Google Scholar 

  • Bertogna M, Cirinei M, Lipari G (2005) Improved schedulability analysis of EDF on multiprocessor platforms. In: Proc of the 17th Euromicro conference on real-time systems, Palma de Mallorca, Spain, pp 209–218

  • Cho S, Lee S-K, Han A, Lin K-J (2002) Efficient real-time scheduling algorithms for multiprocessor systems. IEICE Trans Commun E 85-B(12):2859–2867

    Google Scholar 

  • Cirinei M (2007) Exploiting the power of multiprocessors for real-time systems. PhD thesis, Scuola Superiore S Anna, Pisa, Italy

  • Cirinei M, Baker TP (2007) EDZL scheduling analysis. In: Proc EuroMicro conference on real-time systems, to appear

  • Goossens J, Funk S, Baruah S (2003) Priority-driven scheduling of periodic task systems on multiprocessors. Real Time Syst 25(2–3):187–205

    Article  MATH  Google Scholar 

  • Ha R (1995) Validating timing constraints in multiprocessor and distributed systems. PhD thesis, Dept of Computer Science, University of Illinois, Urbana-Champaign, IL

  • Ha R, Liu JWS (1994) Validating timing constraints in multiprocessor and distributed real-time systems. In: Proc of the 14th IEEE international conf on distributed computing systems, Poznan, Poland. IEEE Computer Society, Los Alamitos, pp 162–171

    Google Scholar 

  • Park M, Han S, Kim H, Cho S, Cho Y (2005) Comparison of deadline-based scheduling algorithms for periodic real-time tasks on multiprocessor. IEICE Trans Inf Syst E 88-D(3):658–661

    Article  Google Scholar 

  • Piao X, Han S, Kim H, Park M, Cho Y, Cho S (2006) Predictability of earliest deadline zero laxity algorithm for multiprocessor real time systems. In: Proc of the 9th IEEE international symposium on object and component-oriented real-time distributed computing, Gjeongju, Korea

  • Sprunt B, Sha L, Lehoczky L (1989) Aperiodic task scheduling for hard real-time systems. Real-Time Syst 1(1):27–60

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Department of Computer Science, Florida State University, Tallahassee, FL, 32306-4530, USA

    Theodore P. Baker

  2. ReTIS Lab, Scuola Superiore Sant’Anna, Pisa, Italy

    Michele Cirinei & Marko Bertogna

Authors
  1. Theodore P. Baker
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Michele Cirinei
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Marko Bertogna
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Theodore P. Baker.

Additional information

This is an extended version of the ECRTS’07 paper of Cirinei and Baker (2007), with corrections of some flaws in that original paper and a new iterative schedulability test based on Cirinei (2007).

This material is based upon work supported in part by the National Science Foundation under Grant No. 0509131, and a DURIP grant from the Army Research Office.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Baker, T.P., Cirinei, M. & Bertogna, M. EDZL scheduling analysis. Real-Time Syst 40, 264–289 (2008). https://doi.org/10.1007/s11241-008-9061-6

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11241-008-9061-6

Keywords

Search

Navigation