Improved Schedulability Analysis of Real-Time Transactions with Earliest Deadline Scheduling

2005 ◽  
Author(s):  
R. Pellizzoni ◽  
G. Lipari
Keyword(s):  
Real Time ◽  
Schedulability Analysis ◽  
Earliest Deadline ◽  
Deadline Scheduling

scholarly journals Limited Non-Preemptive EDF Scheduling for a Real-Time System with Symmetry Multiprocessors

Symmetry ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 172 ◽  
Author(s):  
Hoyoun Lee ◽  
Jinkyu Lee
Keyword(s):  
Real Time ◽  
Scheduling Algorithm ◽  
Schedulability Analysis ◽  
Timing Constraints ◽  
Limited Information ◽  
Time System ◽  
Real Time System ◽  
System A ◽  
The Future ◽  
Earliest Deadline

In a real-time system, a series of jobs invoked by each task should finish its execution before its deadline, and EDF (Earliest Deadline First) is one of the most popular scheduling algorithms to meet such timing constraints of a set of given tasks. However, EDF is known to be ineffective in meeting timing constraints for non-preemptive tasks (which disallow any preemption) when the system does not know the future job release patterns of the tasks. In this paper, we develop a scheduling algorithm for a real-time system with a symmetry multiprocessor platform, which requires only limited information about the future job release patterns of a set of non-preemptive tasks, called LCEDF. We then derive its schedulability analysis that provides timing guarantees of the non-preemptive task set on a symmetry multiprocessor platform. Via simulations, we demonstrate the proposed schedulability analysis for LCEDF significantly improves the schedulability performance in meeting timing constraints of a set of non-preemptive tasks up to 20.16%, compared to vanilla non-preemptive EDF.

scholarly journals A new sufficient schedulability analysis for hybrid scheduling

2016 ◽  
Vol 26 (3) ◽  
pp. 683-692 ◽  
Author(s):  
Fengxiang Zhang ◽  
Yanfeng Zhai ◽  
Jianwei Liao
Keyword(s):  
Real Time ◽  
Schedulability Analysis ◽  
Real Time Systems ◽  
Hybrid Scheduling ◽  
Acceptance Ratio ◽  
Schedulability Test ◽  
Time Systems ◽  
Task Systems ◽  
Task Parameters ◽  
Earliest Deadline

Abstract Earliest deadline first (EDF) and fixed priority (FP) are the most commonly used and studied scheduling algorithms for real-time systems. This paper focuses on combining the EDF and FP strategies in one system. We provide a new sufficient schedulability analysis for real-time hybrid task systems which are scheduled by EDF and FP. The proposed analysis has a polynomial time complexity and no restrictions on task parameters, where the relative deadline of each task could be less than, equal to, or greater than its period. By extensive experiments, we show that our proposed analysis significantly improves the acceptance ratio compared with the existing results of the sufficient schedulability test for hybrid scheduling systems.

Schedulability Analysis of Graph-Based Real-Time Task Model with Precedence Constraints

2018 ◽  
Vol 28 (11n12) ◽  
pp. 1575-1595
Author(s):  
Rongfei Xu ◽  
Li Zhang ◽  
Ning Ge ◽  
Xavier Blanc
Keyword(s):  
Real Time ◽  
Optimization Technique ◽  
Schedulability Analysis ◽  
Precedence Constraints ◽  
Scheduling Policy ◽  
Large Sets ◽  
Task Model ◽  
Periodic Models ◽  
Time Systems ◽  
Earliest Deadline

The timing requirements of real-time systems can be guaranteed by well-designed scheduling policies. The analysis of such scheduling uses an abstract task model of the system to diagnose the practicability of timing requirements. The task models have evolved from periodic models to more sophisticated graph-based ones, among which digraph real-time (DRT) task model is the most applicable because of its good expressiveness and analysis efficiency. However, the DRT model cannot support the commonly used precedence constraints within or between tasks. In this paper, we propose a new task model that extends the DRT model to support precedence constraints. Based on our model, we present two methods of uniprocessor schedulability analysis for static priority scheduling policy and earliest deadline first (EDF) scheduling policy. We also introduce an optimization technique to improve the efficiency of model analysis. Our experiments show that, despite a high computational complexity of the problem, our approach scales very well for large sets of tasks with precedence constraints.

scholarly journals Modeling and schedulability analysis in the development of real-time distributed Ada systems

2002 ◽  
Author(s):  
J. Javier Gutiérrez ◽  
José M. Drake ◽  
Michael González Harbour ◽  
Julio L. Medina
Keyword(s):  
Real Time ◽  
Schedulability Analysis

scholarly journals Generalized Weakly Hard Schedulability Analysis for Real-Time Periodic Tasks

2021 ◽  
Vol 20 (1) ◽  
pp. 1-26
Author(s):  
Paolo Pazzaglia ◽  
Youcheng Sun ◽  
Marco Di Natale
Keyword(s):  
Real Time ◽  
Schedulability Analysis ◽  
Periodic Tasks ◽  
Time Periodic

scholarly journals Logic-based schedulability analysis for compositional hard real-time embedded systems

2015 ◽  
Vol 12 (1) ◽  
pp. 56-64 ◽  
Author(s):  
André de Matos Pedro ◽  
David Pereira ◽  
Luís Miguel Pinho ◽  
Jorge Sousa Pinto
Keyword(s):  
Embedded Systems ◽  
Real Time ◽  
Schedulability Analysis ◽  
Hard Real Time
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