Scheduling with unit processing and communication times on a ring network: Approximation results

  • Chams Lahlou
Workshop 17 Scheduling and Load Balancing
Part of the Lecture Notes in Computer Science book series (LNCS, volume 1124)


We consider the problem of scheduling UET-UCT task graphs on a ring network of m processors, in order to minimize the makespan. We show that no polynomial-time algorithm with relative performance better than 4/3 can exist in that case (unless P=NP), and prove that the relative performance g of the general list scheduling algorithm proposed by Rayward-Smith is such that [√m]≤g ≲-1 + 3/8m −1/2m, for m even.


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Copyright information

© Springer-Verlag Berlin Heidelberg 1996

Authors and Affiliations

  • Chams Lahlou
    • 1
  1. 1.Université Pierre et Marie CurieParis Cedex 05France

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