Sensitivity analysis of real-time task sets
Though schedulability analysis has matured to the point where it is now possible to analyse realistic systems, there is still a lack of flexibility as far as the designer is concerned. Feasibility tests often provide little or no indication of the changes in task timing characteristics required to achieve a feasible system, nor any indication of the extent to which the worst case execution times of tasks may be increased without causing deadlines to be missed (in the case of a feasible system). In practice, however, it is useful to know how sensitive system feasibility is to changes in task timing characteristics. We give a general approach to the sensitivity analysis of task sets, which aids system developers in incorporating changes to the system whilst ensuring that the schedulability guarantees remain intact.
KeywordsBinary Search Schedulability Analysis High Priority Task Task Response Time Lower Priority Task
Unable to display preview. Download preview PDF.
- 1.N. C. Audsley, A. Burns, M.F. Richardson, K. Tindell, and A.J. Wellings. Applying New Scheduling Theory to Static Priority Pre-emptive Scheduling. Software Engineering Journal, 8(5):284–292, September 1993.Google Scholar
- 2.A. Burns, R.I. Davis, and S. Punnekkat. Feasibility and Sensitivity Analysis of Fault-tolerant task sets. Submitted for Publication, March 1996.Google Scholar
- 4.M. H. Klein, T. Ralya, B. Pollak, R. Obebza, and M. G. Harbour, editors. Guide to Rate Monotonic Analysis for Real-Time Systems. Kluwer Academic Publishers, 1993.Google Scholar
- 5.J.P. Lehoczky, L. Sha, and Y. Ding. The Rate Monotonic Scheduling Algorithm — Exact characterization and average case behaviour. Proceedings of IEEE Real-Time Systems Symposium, pages 166,171, December 1989.Google Scholar
- 6.S. Punnekkat. Schedulability Analysis for Fault Tolerant Real-time Systems. PhD thesis, Dept. Computer Science, University of York, June 1997.Google Scholar
- 10.R. Yerraballi, R. Mukkamala, K. Maly, and H.A. Wahab. Issues in Schedulability Analysis of Real-Time Systems. Proceedings of Seventh Euromicro Workshop on Real-Time Systems, pages 87–92, June 1995.Google Scholar