Server Scheduling in the Weighted ℓp Norm

  • Nikhil Bansal
  • Kirk Pruhs
Part of the Lecture Notes in Computer Science book series (LNCS, volume 2976)


We explain how the apparent goals of the Unix CPU scheduling policy can be formalized using the weighted ℓ p norm of flows. We then show that the online algorithm, Highest Density First (HDF), and the nonclairvoyant algorithm, Weighted Shortest Elapsed Time First (WSETF), are almost fully scalable. That is, they are (1 + ε)-speed O(1)-competitive. Even for unit weights, it was known that there is no O(1)-competitive algorithm. We also give a generic way to transform an algorithm A in an algorithm B in such a way that if A is O(1)-speed O(1)-competitive with respect to some ℓ p norm of flow then B is O(1)-competitive with respect to the ℓ p norm of completion times. Further, if A is online (nonclairvoyant) then B is online (nonclairvoyant). Combining these results gives an O(1)-competitive nonclairvoyant algorithm for ℓ p norms of completion times.


Completion Time Competitive Ratio Online Algorithm Exponential Weighted Moving Average Competitive Algorithm 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.


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Copyright information

© Springer-Verlag Berlin Heidelberg 2004

Authors and Affiliations

  • Nikhil Bansal
    • 1
  • Kirk Pruhs
    • 2
  1. 1.Department of Computer ScienceCarnegie Mellon UniversityUSA
  2. 2.Department of Computer ScienceUniversity of PittsburghUSA

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