scholarly journals Performance Evaluation of New Joint EDF-RM Scheduling Algorithm for Real Time Distributed System

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Rashmi Sharma ◽  
Nitin
Keyword(s):  
Real Time ◽  
Distributed System ◽  
Scheduling Algorithm ◽  
Earliest Deadline First ◽  
Time System ◽  
Real Time System ◽  
Main Target ◽  
Migration Mechanism ◽  
Simulation Results ◽  
Earliest Deadline

In Real Time System, the achievement of deadline is the main target of every scheduling algorithm. Earliest Deadline First (EDF), Rate Monotonic (RM), and least Laxity First are some renowned algorithms that work well in their own context. As we know, there is a very common problem Domino's effect in EDF that is generated due to overloading condition (EDF is not working well in overloading situation). Similarly, performance of RM is degraded in underloading condition. We can say that both algorithms are complements of each other. Deadline missing in both events happens because of their utilization bounding strategy. Therefore, in this paper we are proposing a new scheduling algorithm that carries through the drawback of both existing algorithms. Joint EDF-RM scheduling algorithm is implemented in global scheduler that permits task migration mechanism in between processors in the system. In order to check the improved behavior of proposed algorithm we perform simulation. Results are achieved and evaluated in terms of Success Ratio (SR), Average CPU Utilization (ECU), Failure Ratio (FR), and Maximum Tardiness parameters. In the end, the results are compared with the existing (EDF, RM, and D_R_EDF) algorithms. It has been shown that the proposed algorithm performs better during overloading condition as well in underloading condition.

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.

Energy Efficient Scheduling Algorithm for Soft Real Time System with High Deadline Meeting Rate on Overload

2014 ◽  
Vol 699 ◽  
pp. 840-845
Author(s):  
Zahereel Ishwar Abdul Khalib ◽  
R. Badlishah Ahmad ◽  
Ong Bi Lynn
Keyword(s):  
Power Consumption ◽  
Real Time ◽  
Scheduling Algorithm ◽  
Simulation Method ◽  
Process Scheduling ◽  
Time System ◽  
Real Time System ◽  
System Load ◽  
Percent Improvement ◽  
Earliest Deadline

The fact that earliest deadline first (EDF) scheduling algorithm behaves unpredictably during overload is an old and existing issue in the field of real time system. In this paper, a new software process scheduling algorithm for soft real time applications is presented. The algorithm is formulated by means of logical reasoning and excessive simulation method. This method is adopted due to the fact that the problem of scheduling a set of periodic task on single processor using non-preemptive scheme is NP-hard in the strong sense. The new algorithm, with inherently less computational complexity is found to improve in power consumption by almost 50 percent at the peak of practical overload which is at 150 percent of system load. At the same system load, the new algorithm also gives a minimum of 16 percent improvement in deadline meeting rate (DMTR) as compared to EDF. Design and formulation of the new algorithm along with graphical results of the power consumption level and the level of the deadline meeting rate of both algorithms will be presented and discuss in detail.

ACO Based Dynamic Scheduling Algorithm for Real-Time Multiprocessor Systems

2013 ◽  
pp. 85-96
Author(s):  
Apurva Shah ◽  
Ketan Kotecha
Keyword(s):  
Real Time ◽  
Computational Models ◽  
Dynamic Scheduling ◽  
Scheduling Algorithm ◽  
Earliest Deadline First ◽  
Multiprocessor Systems ◽  
Individual Agent ◽  
Collective Foraging ◽  
Time Systems ◽  
Earliest Deadline

The Ant Colony Optimization (ACO) algorithms are computational models inspired by the collective foraging behavior of ants. The ACO algorithms provide inherent parallelism, which is very useful in multiprocessor environments. They provide balance between exploration and exploitation along with robustness and simplicity of individual agent. In this paper, ACO based dynamic scheduling algorithm for homogeneous multiprocessor real-time systems is proposed. The results obtained during simulation are measured in terms of Success Ratio (SR) and Effective CPU Utilization (ECU) and compared with the results of Earliest Deadline First (EDF) algorithm in the same environment. It has been observed that the proposed algorithm is very efficient in underloaded conditions and it performs very well during overloaded conditions also. Moreover, the proposed algorithm can schedule some typical instances successfully which are not possible to schedule using EDF algorithm.

Energy harvesting earliest deadline first scheduling algorithm for increasing lifetime of real time systems

2019 ◽  
Vol 118 (4) ◽  
pp. 160
Author(s):  
G. Madhumita ◽  
G. Rajini ◽  
B. Subisha
Keyword(s):  
Energy Consumption ◽  
Energy Harvesting ◽  
Real Time ◽  
Scheduling Algorithm ◽  
Earliest Deadline First ◽  
Real Time Systems ◽  
Tasks Scheduling ◽  
Time Systems ◽  
Earliest Deadline ◽  
Reducing Energy

In this paper, a new approach for energy minimization in energy harvesting real time systems has been investigated. Lifetime of a real time systems is depend upon its battery life.  Energy is a parameter by which the lifetime of system can be enhanced.  To work continuously and successively, energy harvesting is used as a regular source of energy. EDF (Earliest Deadline First) is a traditional real time tasks scheduling algorithm and DVS (Dynamic Voltage Scaling) is used for reducing energy consumption. In this paper, we propose an Energy Harvesting Earliest Deadline First (EH-EDF) scheduling algorithm for increasing lifetime of real time systems using DVS for reducing energy consumption and EDF for tasks scheduling with energy harvesting as regular energy supply. Our experimental results show that the proposed approach perform better to reduce energy consumption and increases the system lifetime as compared with existing approaches.  

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