New Schedulability Tests for Real-Time Task Sets Scheduled by Deadline Monotonic on Multiprocessors
In this paper, we address the problem of schedulability analysis of a set of real-time periodic (or sporadic) tasks on multiprocessor hardware platforms, under fixed priority global scheduling. In a multiprocessor system with M processors, a global scheduler consists of a single queue of ready tasks for all processors, and the scheduler selects the first M tasks to execute on the M processors. We allow preemption and migration of tasks between processors.
This paper presents two different contributions. First, we derive a sufficient schedulability test for periodic and sporadic task system scheduled with fixed priority when priorities are assigned according to Deadline Monotonic. This test is efficient when dealing with heavy tasks (i.e. tasks with high utilization). Then, we develop an independent analysis for preperiod deadline systems. This leads to a new schedulability test with density and utilization bounds that are tighter than the existing ones.
KeywordsSporadic Task Schedulability Analysis Schedulability Test Global Schedule High Priority Task
Unable to display preview. Download preview PDF.
- 1.Baruah, S., Cohen, N., Plaxton, C., Varvel, D.: Proportionate progress: A notion of fairness in resource allocation. Algorithmica 6 (1996)Google Scholar
- 2.Dhall, S.K., Liu, C.L.: On a real-time scheduling problem. Operations Research 26 (1978)Google Scholar
- 3.Andersson, B., Baruah, S., Jonsson, J.: Static-priority scheduling on multiprocessors. In: Proceedings of the IEEE Real-Time Systems Symposium (2001)Google Scholar
- 4.Baker, T.: Multiprocessor EDF and deadline monotonic schedulability analysis. In: Proceedings of the 24th IEEE International Real-Time Systems Symposium, RTSS 2003 (2003)Google Scholar
- 5.Bertogna, M., Cirinei, M., Lipari, G.: Improved schedulability analysis of EDF on multiprocessor platforms. In: Proceedings of the IEEE Euromicro Conference on Real Time Systems, Mallorca, Spain. IEEE, Los Alamitos (2005)Google Scholar
- 6.Andersson, B.: Static-priority scheduling on multiprocessors. PhD thesis, Department of Computer Engineering, Chalmer University of Technology, Goteborg, Sweden (2003)Google Scholar
- 7.Baker, T.: An analysis of deadline-monotonic schedulability on a multiprocessor. FSU computer science technical report, Department of Computer Science, Florida State University, Tallahassee, Florida (2003), available at http://www.cs.fsu.edu/research/reports