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Competitive Deadline Scheduling via Additional or Faster Processors

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Abstract

This paper studies on-line scheduling in a single-processor system that allows preemption. The aim is to maximize the total value of jobs completed by their deadlines. It is known that if the on-line scheduler is given a processor faster (say, two times faster) than the off-line scheduler, then there exists an on-line algorithm called \({\text{SLACKER}}\) that can achieve an O(1) competitive ratio. In this paper, we show that using additional unit-speed processors instead of a faster processor is a possible but not cost effective way to achieve an O(1) competitive ratio. Specifically, we find that-Θ(log k) unit-speed processors are required, where k is the importance ratio. Another contribution of this paper is an improved analysis of the competitiveness of \({\text{SLACKER}}\); this new analysis enables us to show that \({\text{SLACKER}}\), when extended to multi-processor systems, can still guarantee an O(1) competitive ratio.

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REFERENCES

  • Baruah, S., “Overload tolerance for single-processor workloads,” in IEEE Symp. on Real Time Technology and Application, 1998, pp. 2-11.

  • Baruah, S., G. Koren, D. Mao, B. Mishra, A. Raghunathan, L. Rosier, D. Shasha, and F. Wang, “On the competitiveness of on-line real-time task scheduling,” J. Real-Time Syst., 4, 124-144 (1992).

    Google Scholar 

  • Baruah, S., G. Koren, B. Mishra, A. Raghunathan, L. Rosier and D. Shasha, “On-line scheduling in the presence of overload,” in Proc. IEEE 32nd Annu. Symp. on Foundations of Computer Science, San Juan, Puerto Rico, 1991, pp. 101-110.

  • Berman, P. and C. Coulston, “Speed is more powerful than clairvoyance,” in Proc. 6th Scand. Workshop on Algorithm Theory, Stockholm, Sweden, 8–10 July, 1998, pp. 255-263.

  • Borodin, A. and R. El-Yaniv, Online Computation and Competitive Analysis. Cambridge University Press, Cambridge, United Kingdom, 1998.

    Google Scholar 

  • Brehob, M., E. Torng, and P. Uthaisombut, “Applying extra-resource analysis to load balancing,” in Proc. 11th Annu. ACM-SIAM Symp. on Discrete Algorithms, San Francisco, California 2000, pp. 560-561.

  • Dertouzos, M. L., “Control robotics: the procedural control of physical processes,” in Proc. IFIP Congress, 1974, pp. 807-813.

  • Edmonds, J., in “Scheduling in the dark,”, in Proc. 31st Annu. ACM Symp. on Theory of Computing, 1999, pp. 179-188.

  • Kalyanasundaram, B. and K. R. Pruhs, “Maximizing job completions online,” in Proc. 6th Eur. Symp. on Algorithms, 1998, pp. 235-246.

  • Kalyanasundaram, B. and K. R. Pruhs, “Speed is as powerful as clairvoyance,” J. ACM, 47(4), 617-643 (2000).

    Google Scholar 

  • Koren, G., “Competitive on-line scheduling for overloaded real-time systems,” Department of Computer Science, New York University, 1993.

  • Koren, G. and D. Shasha, “MOCA: A multiprocessor on-line competitive algorithm real-time system scheduling,” Theoretical Comput. Sci., 128, 75-97 (1994).

    Google Scholar 

  • Koren, G. and D. Shasha, “Dover: An optimal on-line scheduling algorithm for overloaded uniprocessor real-time systems,” SIAM J. Computing, 24, 318-339 (1994).

    Google Scholar 

  • Lam, T. W. and K. K. To, “Trade-offs between speed and processor in hard-deadline scheduling,” in Proc. 10th Annu. ACM-SIAM Symp. on Discrete Algorithms, 1999, pp. 623-632.

  • Lam, T. W. and K. K. To, “Performance guarantee for online deadline scheduling in the presence of overload,” in Proc. 10th Annu. ACM-SIAM Symp. on Discrete Algorithms, 2001, pp. 755-764.

  • Cynthia A. P., C. Stein, E. Torng, and J. Wein, “Optimal time-critical scheduling via resource augmentation,” in Proc. 29th Annu. ACM Symp. on Theory of Computing, El Paso, Texas, 1997, pp. 140-149.

  • Sgall, J., “On-line scheduling—a survey,” in A. Fiat and G. Woeginger (eds), On-line Algorithms: The State of the Art, Lecture Notes in Computer Science, Springer and Verlag, 1998, pp. 196-231.

  • Stankovic, J., M. Spuri, K. Ramamritham, and G. Buttazzo, Deadline Scheduling for Real-time Systems EDF and Related Algorithms, Kluwer Academic Publishers Boston, MS, 1998.

    Google Scholar 

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Authors and Affiliations

  1. Department of Computer Science, University of Hong Kong, Hong Kong

    Chiu-Yuen Koo, Tak-Wah Lam, Tsuen-Wan Ngan & Kar-Keung To

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  1. Chiu-Yuen Koo
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  2. Tak-Wah Lam
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  3. Tsuen-Wan Ngan
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  4. Kar-Keung To
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Koo, CY., Lam, TW., Ngan, TW. et al. Competitive Deadline Scheduling via Additional or Faster Processors. Journal of Scheduling 6, 213–223 (2003). https://doi.org/10.1023/A:1022998111685

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