A Review of Sufficient Schedulability Analysis for Fixed Priority Scheduling Systems

2015 ◽  
Vol 741 ◽  
pp. 856-859
Author(s):  
Yan Feng Zhai ◽  
Feng Xiang Zhang
Keyword(s):  
Schedulability Analysis ◽  
Priority Assignment ◽  
Priority Scheduling ◽  
Fixed Priority ◽  
Fixed Priority Scheduling ◽  
Rate Monotonic ◽  
Simple Implementation ◽  
Deadline Monotonic ◽  
Activation Rates

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.

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

2011 ◽  
Vol 6 (1) ◽  
pp. 187 ◽  
Author(s):  
Doina Zmaranda ◽  
Gianina Gabor ◽  
Daniela Elena Popescu ◽  
Codruta Vancea ◽  
Florin Vancea
Keyword(s):  
Real Time ◽  
Schedulability Analysis ◽  
Scheduling Algorithms ◽  
Real Time Systems ◽  
Priority Scheduling ◽  
Fixed Priority ◽  
Fixed Priority Scheduling ◽  
Rate Monotonic ◽  
Real Time Applications ◽  
Time Systems

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.

A Review of Hierarchical Fixed Priority Scheduling

2014 ◽  
Vol 536-537 ◽  
pp. 566-569
Author(s):  
Feng Xiang Zhang
Keyword(s):  
Real Time ◽  
Schedulability Analysis ◽  
Priority Scheduling ◽  
Scheduling Policies ◽  
Fixed Priority ◽  
Fixed Priority Scheduling ◽  
Priority Algorithms ◽  
Priority Systems ◽  
Real Time Applications ◽  
Global And Local

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.

Schedulability Analysis of Fixed Priority Servers for Scheduling Aperiodic Real-Time Tasks – A Review

2014 ◽  
Vol 651-653 ◽  
pp. 1933-1936
Author(s):  
Feng Xiang Zhang
Keyword(s):  
Real Time ◽  
Schedulability Analysis ◽  
Timing Constraints ◽  
Sporadic Tasks ◽  
Fixed Priority ◽  
Rate Monotonic ◽  
Aperiodic Tasks ◽  
Deadline Monotonic ◽  
Priority Algorithm

This paper focus on the schedulability analysis of fixed priority servers. A number of fixed priority servers and their schedulability analysis are reviewed, these results and properties can be used for constructing systems with different timing constraints, where real-time tasks with hard deadlines and the soft aperiodic tasks can be scheduled in the same system. The aperiodic tasks in the fixed priority servers are not preemptable, and they are scheduled in a first-come first-served manner. There is only one server with many periodic or sporadic tasks in the system. The tasks and the server are scheduled by a fixed priority algorithm such as rate monotonic or deadline monotonic.

scholarly journals A faster exact schedulability analysis for fixed-priority scheduling

2006 ◽  
Vol 79 (12) ◽  
pp. 1744-1753 ◽  
Author(s):  
Wan-Chen Lu ◽  
Jen-Wei Hsieh ◽  
Wei-Kuan Shih ◽  
Tei-Wei Kuo
Keyword(s):  
Schedulability Analysis ◽  
Priority Scheduling ◽  
Fixed Priority ◽  
Fixed Priority Scheduling
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