scholarly journals Using Fixed Priority Pre-emptive Scheduling in Real-Time Systems

Author(s):  
Doina Zmaranda ◽  
Gianina Gabor ◽  
Daniela Elena Popescu ◽  
Codruta Vancea ◽  
Florin Vancea

For real-time applications, task scheduling is a problem of paramount importance. Several scheduling algorithms were proposed in the literature, starting from static scheduling or cyclic executives which provide very deterministic yet inflexible behaviour, to the so called best-effort scheduling, which facilitates maximum run-time flexibility but allows only probabilistic predictions of run-time performance presenting a non-predictable and nondeterministic solution. Between these two extremes lies fixed priority scheduling algorithms, such as Rate Monotonic, that is not so efficient for real-time purposes but exhibits a predictable approach because scheduling is doing offline and guarantees regarding process deadlines could be obtained using appropriate analysis methods. This paper investigates the use of Rate Monotonic algorithm by making adjustments in order to make it more suitable for real-time applications. The factors that motivate the interest for fixed priority scheduling algorithms such Rate Monotonic when doing with real-time systems lies in its associated analysis that could be oriented in two directions: schedulability analysis and analysis of process interactions. The analyzing process is carried out using a previously implemented framework that allows modelling, simulation and schedulability analysis for a set of real-time system tasks, and some of the results obtained are presented.

2018 ◽  
Vol 27 (10) ◽  
pp. 1850165
Author(s):  
Meiling Han ◽  
Tianyu Zhang ◽  
Yuhan Lin ◽  
Zhiwei Feng ◽  
Qingxu Deng

The increasing demands for processor performance are driving system designers to adopt multiprocessors. In this paper, we study global fixed priority scheduling in multiprocessor real-time systems and introduce a technique for improving the schedulability. The key idea is to construct execution dependency for selected tasks to leverage slack time and reduce the interference between high-priority and low-priority tasks. Thus, more lower-priority tasks are enabled to be scheduled. Further, we provide a response time analysis method which takes the execution constraint of tasks into consideration. Extensive simulation results indicate that the proposed approach outperforms existing work in terms of acceptance ratio.


2014 ◽  
Vol 536-537 ◽  
pp. 566-569
Author(s):  
Feng Xiang Zhang

This paper focus on two level hierarchical scheduling where several real-time applications are scheduled by the fixed priority algorithms. The application with its real-time tasks is bound to a server which can be modeled as a sporadic task with special care for the schedulability analysis. Different scheduling policies and servers can be applied for hierarchical fixed priority systems, this paper gives a closer review of schedulability analysis for applications and tasks when the global and local schedulers of a system are fixed priority.


1996 ◽  
Vol 33 (1) ◽  
pp. 57-63 ◽  
Author(s):  
Dong-Won Park ◽  
Swaminathan Natarajan ◽  
Arkady Kanevsky

2019 ◽  
Vol 152 ◽  
pp. 120-133 ◽  
Author(s):  
Jiankang Ren ◽  
Zichuan Xu ◽  
Chao Yu ◽  
Chi Lin ◽  
Guowei Wu ◽  
...  

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