scholarly journals A Novel Amended Dynamic Round Robin Scheduling Algorithm for Timeshared Systems

2019 ◽  
Vol 17 (1) ◽  
pp. 90-98 ◽  
Author(s):  
Uferah Shafi ◽  
Munam Shah ◽  
Abdul Wahid ◽  
Kamran Abbasi ◽  
Qaisar Javaid ◽  
...  
Keyword(s):  
Operating System ◽  
Scheduling Algorithm ◽  
Turnaround Time ◽  
Round Robin ◽  
Processing Unit ◽  
Cpu Scheduling ◽  
Central Processing ◽  
Quantum Time ◽  
Simulation Results ◽  
Burst Time

Central Processing Unit (CPU) is the most significant resource and its scheduling is one of the main functions of an operating system. In timeshared systems, Round Robin (RR) is most widely used scheduling algorithm. The efficiency of RR algorithm is influenced by the quantum time, if quantum is small, there will be overheads of more context switches and if quantum time is large, then given algorithm will perform as First Come First Served (FCFS) in which there is more risk of starvation. In this paper, a new CPU scheduling algorithm is proposed named as Amended Dynamic Round Robin (ADRR) based on CPU burst time. The primary goal of ADRR is to improve the conventional RR scheduling algorithm using the active quantum time notion. Quantum time is cyclically adjusted based on CPU burst time. We evaluate and compare the performance of our proposed ADRR algorithm based on certain parameters such as, waiting time, turnaround time etc. and compare the performance of our proposed algorithm. Our numerical analysis and simulation results in MATLAB reveals that ADRR outperforms other well-known algorithms such as conventional Round Robin, Improved Round Robin (IRR), Optimum Multilevel Dynamic Round Robin (OMDRR) and Priority Based Round Robin (PRR)

scholarly journals Priority based round robin (PBRR) CPU scheduling algorithm

2019 ◽  
Vol 9 (1) ◽  
pp. 190
Author(s):  
Sonia Zouaoui ◽  
Lotfi Boussaid ◽  
Abdellatif Mtibaa
Keyword(s):  
Operating System ◽  
Real Time ◽  
Waiting Time ◽  
Scheduling Algorithm ◽  
Scheduling Algorithms ◽  
Turnaround Time ◽  
Round Robin ◽  
New Approach ◽  
Real Time Operating System ◽  
Cpu Scheduling

<p>This paper introduce a new approach for scheduling algorithms which aim to improve real time operating system CPU performance. This new approach of CPU Scheduling algorithm is based on the combination of round-robin (RR) and Priority based (PB) scheduling algorithms. This solution maintains the advantage of simple round robin scheduling algorithm, which is reducing starvation and integrates the advantage of priority scheduling. The proposed algorithm implements the concept of time quantum and assigning as well priority index to the processes. Existing round robin CPU scheduling algorithm cannot be dedicated to real time operating system due to their large waiting time, large response time, large turnaround time and less throughput. This new algorithm improves all the drawbacks of round robin CPU scheduling algorithm. In addition, this paper presents analysis comparing proposed algorithm with existing round robin scheduling algorithm focusing on average waiting time and average turnaround time.</p>

scholarly journals Dynamic Round Robin CPU Scheduling Algorithm Based on K-Means Clustering Technique

2020 ◽  
Vol 10 (15) ◽  
pp. 5134
Author(s):  
Samih M. Mostafa ◽  
Hirofumi Amano
Keyword(s):  
Operating System ◽  
Waiting Time ◽  
Scheduling Algorithm ◽  
Scheduling Algorithms ◽  
Turnaround Time ◽  
Round Robin ◽  
Time Cost ◽  
Cpu Scheduling ◽  
Scheduling Policy ◽  
Service Period

Minimizing time cost in time-shared operating system is the main aim of the researchers interested in CPU scheduling. CPU scheduling is the basic job within any operating system. Scheduling criteria (e.g., waiting time, turnaround time and number of context switches (NCS)) are used to compare CPU scheduling algorithms. Round robin (RR) is the most common preemptive scheduling policy used in time-shared operating systems. In this paper, a modified version of the RR algorithm is introduced to combine the advantageous of favor short process and low scheduling overhead of RR for the sake of minimizing average waiting time, turnaround time and NCS. The proposed work starts by clustering the processes into clusters where each cluster contains processes that are similar in attributes (e.g., CPU service period, weights and number of allocations to CPU). Every process in a cluster is assigned the same time slice depending on the weight of its cluster and its CPU service period. The authors performed comparative study of the proposed approach and popular scheduling algorithms on nine groups of processes vary in their attributes. The evaluation was measured in terms of waiting time, turnaround time, and NCS. The experiments showed that the proposed approach gives better results.

scholarly journals Round Robin Scheduling Algorithm based on Dynamic time quantum

2019 ◽  
Vol 8 (6) ◽  
pp. 593-595
Keyword(s):  
Operating System ◽  
Waiting Time ◽  
Optimal Algorithm ◽  
Scheduling Algorithm ◽  
Round Robin ◽  
Cpu Scheduling ◽  
Time Quantum ◽  
Turn Around Time ◽  
Dynamic Time ◽  
Burst Time

After studying various CPU scheduling algorithms in Operating System, Round Robin scheduling algorithm is found to be most optimal algorithm in timeshared systems because of the static time quantum that is designated for every process. The efficacy of Round Robin algorithm entirely depends on the static time quantum that is being selected. After studying and analyzing Round Robin algorithm, I have proposed a new modified Round Robin algorithm that is based on shortest remaining burst time which has resulted in dynamic time quantum in place of static time quantum. This improves the performance of existing algorithm by reducing average waiting time and turn-around time and minimizing the number of context switches.

scholarly journals Comparison Analysis of CPU Scheduling FCFS, SJF and Round Robin

2017 ◽  
Author(s):  
Andysah Putera Utama Siahaan
Keyword(s):  
Task Scheduling ◽  
Waiting Time ◽  
Scheduling Algorithm ◽  
Round Robin ◽  
The Other ◽  
Comparison Analysis ◽  
Cpu Scheduling ◽  
Multiple Processes ◽  
Burst Time ◽  
Better Than

Task scheduling is needed to maintain every process that comes with a processor in parallel processing. In several conditions, not every algorithm works better on the significant problem. Sometimes FCFS algorithm is better than the other in short burst time while Round Robin is better for multiple processes in every single time. However, it cannot be predicted what process will come after. Average Waiting Time is a standard measure for giving credit to the scheduling algorithm. Several techniques have been applied to maintain the process to make the CPU performance in normal. The objective of this paper is to compare three algorithms, FCFS, SJF, and Round Robin. The target is to know which algorithm is more suitable for the certain process.

scholarly journals Multithread Affinity Scheduling Using a Decision Maker

2018 ◽  
Vol 6 (4) ◽  
Author(s):  
Shatha K. Jawad ◽  
Ronald P. Uhlig ◽  
Bhaskar Sinha ◽  
Mohammad N. Amin ◽  
Pradip Peter Dey
Keyword(s):  
Operating System ◽  
Decision Maker ◽  
Scheduling Algorithm ◽  
Two Dimensions ◽  
Design Approach ◽  
Multiprocessor System ◽  
Processing Unit ◽  
New Approach ◽  
Central Processing ◽  
Level Scheduling

In a multiprocessor-multithread Operating System (OS), scheduling has two dimensions. The operating system has to decide which thread to run and which Central Processing Unit (CPU) to run it on. Assume the threads are independent and each thread has a priority, the operating system selects a thread with the highest priority and assigns it to the first free CPU. Usually, each CPU has its private cache. To increase the throughput of the system, it is preferred to use affinity scheduling. The affinity scheduling concept is to make an effort to have a thread run on the same CPU it ran on the last time. The existing affinity scheduling is implemented by using a two-level scheduling algorithm. In this paper a new approach is designed to implement independent multithread scheduling on a multiprocessor system. The design approach uses a decision maker to compute a new priority for each ready thread according to the thread pre-priority and affinity. The results show that by using the new priority, the goal of having affinity is satisfied in addition to taking the pre-priority of the thread in consideration. Also, the design approach reduces the scheduling time because it implements affinity scheduling and priority scheduling by employing a one level scheduling algorithm.

scholarly journals Optimal Round Robin CPU Scheduling Algorithm Using Manhattan Distance

2017 ◽  
Vol 7 (6) ◽  
pp. 3664 ◽  
Author(s):  
N. Srilatha ◽  
M. Sravani ◽  
Y. Divya
Keyword(s):  
Waiting Time ◽  
Scheduling Algorithm ◽  
Round Robin ◽  
Manhattan Distance ◽  
Cpu Scheduling ◽  
Cpu Time ◽  
Interactive Environment ◽  
Time Quantum ◽  
Burst Time ◽  
Better Than

In Round Robin Scheduling the time quantum is fixed and then processes are scheduled such that no process get CPU time more than one time quantum in one go. The performance of Round robin CPU scheduling algorithm is entirely dependent on the time quantum selected. If time quantum is too large, the response time of the processes is too much which may not be tolerated in interactive environment. If time quantum is too small, it causes unnecessarily frequent context switch leading to more overheads resulting in less throughput. In this paper a method using Manhattan distance has been proposed that decides a quantum value. The computation of the time quantum value is done by the distance or difference between the highest burst time and lowest burst time. The experimental analysis also shows that this algorithm performs better than RR algorithm and by reducing number of context switches, reducing average waiting time and also the average turna round time.

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