Journal of the Korea Institute of Information and Communication Engineering (한국정보통신학회논문지)

The Korea Institute of Information and Commucation Engineering (한국정보통신학회)
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Real-Time Aperiodic Tasks Scheduling Using Improved Synthetic Utilization on Multiprocessor Systems

다중프로세서 시스템상의 개선된 합성 이용율을 이용한 실시간 비주기 태스크 스케줄링

  • Received : 2013.09.24
  • Accepted : 2013.11.13
  • Published : 2014.01.31
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Abstract

Abdelzaher et al. proposed an algorithm to determine the schedulability of aperiodic tasks on multiprocessor systems, and proved that the aperiodic tasks are schedulable if the upperbound of synthetic utilization is less than or equal to 0.59. But this algorithm has a drawback in that if some tasks, even though they are completed and have no more execution times, are included in the current invocation set, their execution times and deadlines are added to the synthetic utilization. This may lead to a problem in which actually schedulable tasks are decided not to be schedulable. In this paper, we recognize the above mentioned problem and propose an improved synthetic utilization method that can be used to schedule aperiodic tasks more efficiently on multiprocessor systems.

다중프로세서 시스템에서 임의의 시점에 비주기 태스크들의 스케줄링 가능성을 판단하기위한 알고리즘으로서 합성 이용율이 Abdelzaher등에 의해 제시되었는데, 이들은 임의의 시점에 합성이용율의 상한 값인 0.59를 넘지 않으면 비주기 태스크들이 스케줄링 가능 하다는 것을 증명 하였다. 하지만 이 방법은 비주기 태스크들의 프로세서 이용율 계산 시 태스크가 실제 모든 실행시간을 종료하여 더 이상의 실행시간을 갖지 않더라도 현재요청집합에 속해 있다면 실행시간과 종료시한을 합성 이용율에 포함하기 때문에 스케줄링 가능한 태스크들이 실행 불가능한 경우로 판단되는 문제점을 가지고 있다. 본 논문에서는 이러한 문제점을 해결하여 다중프로세서 시스템에서 더 많은 비주기 태스크들이 스케줄링 가능 하도록 개선된 합성 이용율 방법을 제시하였다.

Keywords

References

  1. C. L. Liu and J. W. Layland, "Scheduling algorithms for multiprogramming in hard real time environment", Journal of the ACM, vol. 20, pp. 46-61, Jan. 1973. https://doi.org/10.1145/321738.321743
  2. H. Chetto and M. Chetto, "Some results of the earliest deadline first scheduling algorithm", IEEE Transactions on Software Engineering, vol. 15, no. 10, pp. 1261-1268, Oct. 1989. https://doi.org/10.1109/TSE.1989.559777
  3. Kim, In-Guk, Kim, Dong-Yoon and Hong, Man-pyo, "Real-time scheduling of tasks that contain the external blocking intervals", Proceedings Second International Workshop on RTCSA '95, pp. 54-59, 1994.
  4. A. Wellings, M. Richardson, A. Burns, N. Audsley, K. Tindell, "Applying new scheduling theory to static priority preemptive scheduling." Report RTRG 1921120, Dept. of Computer Science, Univ. of York.
  5. J. P. Lehoczky, and S. Ramos-Thuel, "An optimal algorithm for scheduling soft-aperiodic tasks in fixedpriority preemtive systems", in Proceedings of the real- Time Systems Symposium, pp. 110-123, Dec. 1992.
  6. S. R. Thuel and J. P. Lehoczky, "Algorithms for scheduling hard aperiodic tasks in fixed-priority systems using slack stealing", in Proceedings of IEEE Real-Time Systems Symposium, pp. 22-33, Dec. 1995.
  7. T. F. Abdelzaher, V. Sharma, and C. Lu, "A Utilization bound for aperiodic tasks and priority driven scheduling", IEEE Transactions on Computers, vol. 53, no. 3, pp. 334-350, Mar 2004. https://doi.org/10.1109/TC.2004.1261839
  8. T. F. Abdelzaher and C. Lu, "Schedulability analysis and utilization bounds for highly scalable real-time services", in Proceedings of IEEE Real-Time Technology and Applications Symposium, May 2001.
  9. T. F. Abdelzaher and B. Anderson, J. Jonsson, V. Sharma, and M. Nguyen. "The aperiodic multiprocessor utilization bound for liquid tasks." in Real-time and Embedded Technology and Applications Symposium, San Jose, California, September 2002.
  10. T. F. Abdelzaher and V. Sharma. "A synthetic utilization bound for aperiodic tasks with resource requirements." in 15th Euromicro Conference on Real-Time Systems, porto, Portugal, July 2003.
  11. J. Park, M. Ryu, and S. Hong, "Deterministic and statistical admission control for QoS-aware embedded systems", Journal of Embedded Computing, vol. 1, no. 1, 2004.
  12. J. P. Lehoczky, "Real-time queueing theory", in Proceedings of IEEE Real-Time Systems Symposium, pp. 186-195, Dec. 1996.