We explain how the apparent goals of the Unix CPU scheduling policy can be formalized using the weighted lp 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 + epsilon)-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 lp 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
lp norms of completion times.
By: Nikhil Bansal, Kirk R. Pruhs
Published in: RC23170 in 2004
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