An Improved Rate Monotonic Schedulability Test Algorithm

<p>Real-Time Monotonic algorithm (RMA) is a widely used static priority scheduling algorithm. For application of RMA at various systems, it is essential to determine the system’s feasibility first. The various existing algorithms perform the analysis by reducing the scheduling points in a given task set. In this paper we propose a schedubility test algorithm, which reduces the number of tasks to be analyzed instead of reducing the scheduling points of a given task. This significantly reduces the number of iterations taken to compute feasibility. This algorithm can be used along with the existing algorithms to effectively reduce the high complexities encountered in processing large task sets. We also extend our algorithm to multiprocessor environment and compare number of iterations with different number of processors. This paper then compares the proposed algorithm with existing algorithm. The expected results show that the proposed algorithm performs better than the existing algorithms.</p>

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Period-Dependent Initial Values for Exact Schedulability Test of Rate Monotonic Systems

2007 IEEE International Parallel and Distributed Processing Symposium ◽

10.1109/ipdps.2007.370352 ◽

2007 ◽

Cited By ~ 5

Author(s):

Wan-Chen Lu ◽

Kwei-Jay Lin ◽

Hsin-Wen Wei ◽

Wei-Kuan Shih

Keyword(s):

Initial Values ◽

Rate Monotonic ◽

Schedulability Test

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Utilization Bound Scheduling Analysis for Nonpreemptive Uniprocessor Architecture Using UML-RT

Modelling and Simulation in Engineering ◽

10.1155/2014/705929 ◽

2014 ◽

Vol 2014 ◽

pp. 1-11

Author(s):

S. Ewins Pon Pushpa ◽

Manamalli Devasigamani

Keyword(s):

Release Time ◽

Periodic Tasks ◽

Task Set ◽

Processor Utilization ◽

Window Analysis ◽

Rate Monotonic ◽

Utilization Bound ◽

Priority Scheme ◽

Schedulability Test ◽

Necessary And Sufficient

The key for adopting the utilization-based schedulability test is to derive the utilization bound. Given the computation times, this paper proposes two utilization bound algorithms to derive interrelease times for nonpreemptive periodic tasks, using a new priority scheme, “Rate Monotonic Algorithm-Shortest Job First.” The obtained task set possesses the advantage of Rate Monotonic Algorithm and Shortest Job First priority scheme. Further, the task set is tested for schedulability, by first deriving a general schedulability condition from “problem window” analysis and, a necessary and sufficient schedulability condition for a task to be scheduled, at any release time are also derived. As a technical contribution, success ratio and effective processor utilization are analyzed for our proposed utilization bound algorithms on a uniprocessor architecture modeled using UML-RT.

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