scholarly journals Convoy Effect Elimination in FCFS Scheduling

2020 ◽  
Vol 9 (3) ◽  
pp. 3218-3221
Keyword(s):  
Operating Systems ◽  
Waiting Time ◽  
Turnaround Time ◽  
Round Robin ◽  
Process Scheduling ◽  
Priority Scheduling ◽  
Average Waiting Time ◽  
Novel Method ◽  
Lengthy Process

One of the important activities of operating systems is process scheduling. There are many algorithms available for scheduling like First Come First Served, Shortest Job First, Priority Scheduling and Round Robin. The fundamental algorithm is First Come First Served. It has some drawback of convoy effect. Convoy effect occurs when the small processes are waiting for lengthy process to complete. In this paper novel method is proposed to reduce convoy effect and to make the Scheduling optimal which reduces average waiting time and turnaround time.

scholarly journals Super Smart Optimized Round Robin

2016 ◽  
Vol 2 (2) ◽  
pp. 19-21
Author(s):  
Achmad Teguh Wibowo
Keyword(s):  
Waiting Time ◽  
Turnaround Time ◽  
Round Robin ◽  
Priority Scheduling ◽  
Average Waiting Time ◽  
First Come First Serve ◽  
Time Average ◽  
Average Turnaround Time

Aspek penting dalam sistem operasi adalah multiprogramming. Multiprogramming adalah proses atau metode yang digunakan untuk mengekssekusi beberapa proses secara bersamaan dalam memori. Tujuan utamanya adalah untuk meminimalkan Average Waiting Time, Average Turnaround Time, dan memaksimalkan penggunaan CPU. Ada berbagai algoritma yang digunakan dalam multiprogramming seperti First Come First Serve (FCFS), Shortest Job First (SJF), Priority Scheduling (PS) dan Round Robin(RR). Diantara semua itu yang paling sering digunakan adalah Round Robin. Round Robin merupakan algoritma penjadwalan yang optimal dengn sistem timeshared. Dalam RR, waktu kuantum bersifat statis dan algoritma ini bergantung pada besarnya kuantum yang dipilih/digunakan. Kuantum inilah yang berpengaruh pada Average Waiting Time dan Average Turnaround Time nantinya. Tujuan dari makalah ini adalah mengusulkan algoritma yang lebih baik daripada Round Robin sederhana dan Smart Optimized Round Robin sebelumnya.

scholarly journals Design of Optimal Scheduler for Process Scheduling

2020 ◽  
Vol 9 (3) ◽  
pp. 3759-3761
Keyword(s):  
Operating Systems ◽  
Waiting Time ◽  
Arrival Time ◽  
Turnaround Time ◽  
Process Scheduling ◽  
Cpu Scheduling ◽  
Cpu Utilization ◽  
Optimal Scheduler

CPU Scheduling takes plays an important role in multiprogramming systems. There are several programs present in memory. It is the responsibility of operating systems to select the process and assign it to CPU. There are various algorithms available for CPU Scheduling. The algorithm’s performance depends on various factors like arrival time, priority etc. This paper helps to select the best algorithm by comparing various algorithms under the same condition and analyzed them based on various factors like waiting time, turnaround time, CPU utilization, Throughput.

scholarly journals An Improved Round Robin CPU Scheduling Algorithm based on Priority of Process

2018 ◽  
Vol 7 (4.5) ◽  
pp. 238 ◽  
Author(s):  
Govind Prasad Arya ◽  
Kumar Nilay ◽  
Devendra Prasad
Keyword(s):  
Operating System ◽  
Waiting Time ◽  
Scheduling Algorithm ◽  
Round Robin ◽  
Process Scheduling ◽  
Cpu Scheduling ◽  
Average Waiting Time ◽  
Time Quantum ◽  
First Come First Serve ◽  
Time Changes

The most important and integral part of a computer system is its operating system. Scheduling various resources is one of the most critical tasks an operating system needs to perform. Process scheduling being one of those tasks, involves various techniques that define how more than one processes can be executed simultaneously. The primary aim here is to the system more efficient and faster. The fundamental scheduling algorithms are: First Come First Serve (FCFS), Round Robin, Priority Based Scheduling, and Shortest Job First (SJF). This paper focuses on Round Robin Scheduling algorithm and various issues related to it. One major issue in RR scheduling is determining the length of Time Quantum. If the Time Quantum is too large RR scheduling behaves as FCFS. On the other hand, if it is too small it forces considerable increase in the number of context switches. Our main objective is to overcome this limitation of traditional RR scheduling algorithm and maximize CPU utilization, further, leading to more efficient and faster system. Here we propose an algorithm that categorizes available processes into High Priority processes and Low Priority process. The proposed algorithm reduces the average waiting time of High Priority processes in all cases and of Low Priority processes in not all but some cases. The overall waiting time changes on the basis of set of processes considered. The simulation results justify that the proposed schemes reduces the overall average waiting time when compared to the existing schemes. 

scholarly journals Scheduling Schemes in Dynamic Multilevel Packet Scheduling in WSN

2019 ◽  
Vol 8 (2) ◽  
pp. 3800-3804
Keyword(s):  
Real Time ◽  
Waiting Time ◽  
Packet Scheduling ◽  
Turnaround Time ◽  
Priority Level ◽  
Average Waiting Time ◽  
Level 3 ◽  
Overall Performance ◽  
The Individual ◽  
Priority Levels

As focusing on the scheduling schemes, there are many scheduling schemes for multilevel. So the paper is concentrating to compare the scheduling schemes and producing the average waiting time and turnaround time. If it is minimized then the overall performance may shoot up. In this paper comparison is done between three scheduling schemes Enhanced Dynamic Multilevel Packet scheduling (EDMP), Circular Wait Dynamic Multilevel Packet scheduling (CW-DMP) and Starvation-Free Dynamic Multilevel Packet scheduling (SF-DMP). In all the above schemes there are three priority levels say priority level 1(Pr1), priority level 2(Pr2) and priority level 3(Pr3). Pr1 will comprise the real time tasks, Pr2 containing the non real time remote tasks and non real time local tasks are there in Pr3. In each and every scheme, each and every priority level will be using the individual scheduling technique to schedule the tasks. Also the comparison is done based on waiting time and the turnaround time of the task thereby the average waiting time and the average turnaround time are calculated.

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 Time Slice Calculation for Round Robin Process Scheduling Using NOC

2015 ◽  
Vol 5 (6) ◽  
pp. 1480
Author(s):  
G Siva Nageswara Rao ◽  
N. Srinivasu ◽  
S.V.N. Srinivasu ◽  
G. Rama Koteswara Rao
Keyword(s):  
Scheduling Algorithm ◽  
Turnaround Time ◽  
Round Robin ◽  
Fine Tuning ◽  
New Method ◽  
Time Slice ◽  
Process Scheduling ◽  
Time Duration ◽  
Dynamic Time ◽  
Ready Queue

<p>Process scheduling means allocating a certain amount of CPU time to each of the user processes.  One of the popular scheduling algorithms is the “Round Robin” algorithm, which allows each and every process to utilize the CPU for short time duration.  Processes which finish executing during the time slice are removed from the ready queue.  Processes which do not complete execution during the specified time slice are removed from the front of the queue, and placed at the rear end of the queue. This paper presents an improvisation to the traditional round robin scheduling algorithm, by proposing a new method. The new method represents the time slice as a function of the burst time of the waiting process in the ready queue. Fixing the time slice for a process is a crucial factor, because it subsequently influences many performance parameters like turnaround time, waiting time, response time and the frequency of context switches.  Though the time slot is fixed for each process, this paper explores the fine-tuning of the time slice for processes which do not complete in the stipulated time allotted to them.</p>

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