scholarly journals On the compatibility of exact schedulability tests for global fixed priority pre-emptive scheduling with Audsley’s optimal priority assignment algorithm

2015 ◽  
Vol 52 (1) ◽  
pp. 113-122 ◽  
Author(s):  
Robert I. Davis ◽  
Marko Bertogna ◽  
Vincenzo Bonifaci
2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Saehwa Kim

Preemption threshold scheduling (PTS) enhances real-time schedulability by controlling preemptiveness of tasks. This benefit of PTS highly depends on a proper algorithm that assigns each task feasible scheduling attributes, which are priority and preemption threshold. Due to the existence of an efficient optimal preemption threshold assignment algorithm that works with fully assigned priority orderings, we need an optimal priority assignment algorithm for PTS. This paper analyzes the inefficiency or nonoptimality of the previously proposed optimal priority assignment algorithms for PTS. We develop theorems for exhaustively but safely pruning infeasible priority orderings while assigning priorities to tasks for PTS. Based on the developed theorems, we correct the previously proposed optimal priority assignment algorithm for PTS. We also propose a performance improved optimal priority assignment algorithm for PTS proving its optimality. The empirical evaluation results clearly show the effectiveness of the proposed algorithm.


2015 ◽  
Vol 741 ◽  
pp. 856-859
Author(s):  
Yan Feng Zhai ◽  
Feng Xiang Zhang

This papercarries out a survey of sufficient schedulability analysis forfixed priority (FP) scheduling. The most common used fixed priority assignment is the rate monotonic (RM) algorithm, according to its policy, the task priorities are ordered based on their activation rates, so that the task with the shortest period is assigned the highest priority. However, when each task’s relative deadline is not equal to its period, the RM algorithm is not suitable to assign the task priorities. When relative deadlines are less than or equal to periods,the deadline monotonic (DM) algorithm can be deployed to schedule the tasks. The utilization based schedulability analysis has the advantage of simple implementation, and manyexisting schedulability analyses on uniprocessor are covered.


2008 ◽  
Vol 57 (9) ◽  
pp. 1261-1276 ◽  
Author(s):  
Robert I. Davis ◽  
Attila Zabos ◽  
Alan Burns

2006 ◽  
Vol 99 (3) ◽  
pp. 83-86 ◽  
Author(s):  
Konstantinos Bletsas ◽  
Neil Audsley

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