Scheduling to minimize gaps and power consumption

  • Authors:
  • Erik D. Demaine;Mohammad Ghodsi;Mohammad Taghi Hajiaghayi;Amin S. Sayedi-Roshkhar;Morteza Zadimoghaddam

  • Affiliations:
  • M.I.T., Cambridge, MA;Sharif University of Technology, Tehran, Iran;M.I.T., Cambridge, MA;Sharif University of Technology, Tehran, Iran;Sharif University of Technology, Tehran, Iran

  • Venue:
  • Proceedings of the nineteenth annual ACM symposium on Parallel algorithms and architectures
  • Year:
  • 2007

Quantified Score

Hi-index 0.02

Visualization

Abstract

This paper considers scheduling tasks while minimizing the power consumption of one or more processors, each of which can go to sleep at a fixed cost α. There are two natural versions of this problem, both considered extensively in recent work: minimize the total power consumption (including computation time), or minimize the number of "gaps" in execution. For both versions in a multiprocessor system, we develop a polynomial-time algorithm based on sophisticated dynamic programming. In a generalization of the power-saving problem, where each task can execute in any of a specified set of time intervals, we develop a (1 + 23 α)-approximation, and show that dependence on α is necessary. In contrast, the analogous multi-interval gap scheduling problem is set-cover hard (and thus not o(lg n)-approximable), even in the special cases of just two intervals per job or just three unit intervals per job. We also prove several other hardness-of-approximation results. Finally, we give an O(√n)-approximation for maximizing throughput given a hard upper bound on the number of gaps.