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Feedback Control for Real-time Scheduling ’
| Content Provider | Semantic Scholar |
|---|---|
| Author | Sahoo, Deepak Ranjan Sriram Swaminathan Al-Omari, R. Salapaka, V. Manimaran, G. Somani, A. K. |
| Copyright Year | 2004 |
| Abstract | Most of real-time scheduling algorithms are open-loop algorithms as the scheduling decisions are based on the worst-case estimates of task parameters. They do not continuously observe the performance of the system and do not dynamically adjust the system parameters t o improve performance. In many cases, it is preferable to base scheduling decisions on average-case workload parameters and be ready to deal with bounded transient overloads dynamically. In recent years, the “closed-loop” scheduling has gained importance due to its applicability to many real-world problems wherein the feedback information can be exploited efficiently to adjust task and/or scheduler parameters, thereby improving the system‘s performance. In this paper, we discuss an open-loop dynamic scheduling algorithm that employs a notion of task overlap in the scheduler in order to provide some flexibility in task execution time. Then we present a novel closed-loop approach for dynamically estimating the execution time of tasks based on both deadline miss ratio and task rejection ratio in the system. This approach is highly preferable for firm/soft real-time systems since it provides a firm performance guarantee in terms of deadline misses while achieving a high guarantee ratio. We design proportional-integral controller arid H-infinity controller for closed loop scheduling. We evaluate the performance of the open-loop and the closed-loop approaches using simulation studies. We show that the closed-loop dynamic scheduling offers a better performance over the open-loop scheduling under all practical conditions. |
| File Format | PDF HTM / HTML |
| Alternate Webpage(s) | http://nanodynamics.ece.iastate.edu/research/publications/pdfFiles/Conference/Feedback%20control%20for%20real-time%20scheduling.pdf |
| Language | English |
| Access Restriction | Open |
| Subject Keyword | Algorithm Best, worst and average case Controllers Deny (action) Earliest deadline first scheduling Estimated Gain Loop scheduling Real-time clock Real-time computing Real-time transcription Rejection sampling Run time (program lifecycle phase) Scheduling (computing) Scheduling - HL7 Publishing Domain Simulation |
| Content Type | Text |
| Resource Type | Article |
