%0 Journal Article
%T Designing of 2-Stage CPU Scheduler Using Vague Logic
%A Supriya Raheja
%A Reena Dhadich
%A Smita Rajpal
%J Advances in Fuzzy Systems
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/841976
%X In operating system the CPU scheduler is designed in such a way that all the resources are fully utilized. With static priority scheduling the scheduler ensures that CPU time will be assigned according to the highest priority but ignores other factors; hence it affects the performance. To improve the performance, we propose a new 2-stage vague logic based scheduler. In first stage, scheduler handles the uncertainty of tasks using the proposed vague inference system (VIS). In second stage, scheduler uses a vague oriented priority scheduling (VOPS) algorithm for selection of next process. The goal of this work is to handle the uncertainty as well as to optimize both the average and the amount of variation with respect to performance matrices average waiting time, average turnaround time, and average normalized turnaround time. A simulation using MATLAB is also conducted to evaluate the performance. Simulation results show that the proposed scheduler using VOPS algorithm is better than the scheduler with traditional priority scheduling algorithm. Results are based on the dual concept of fuzzy theory and its generalization, vague theory. Additionally, this work comprises the evaluation of VOPS and shortest job first algorithm. The outcome of proposed VOPS algorithm is much closer to the result obtained by traditional shortest job first. 1. Introduction CPU Scheduler is the main module of any operating system, as it selects the next task to be run. It runs a scheduling algorithm for selection of task. When more than one task is ready to execute, scheduling algorithms will decide which one is to run first. Hence, the designer of scheduler must consider the scheduling algorithm which provides effective throughput. Operating system is not capable to know the exact attributes values of the task, namely, execution time and so forth. Recent developments in priority scheduling have made significantly enhancements to the models considering uncertainty factors. These models accommodate the attributes of tasks with Fuzzy logic. This paper is written with the aim of focusing on the uncertainty and impreciseness of attributes with vague logic and generalized form of fuzzy logic. The vague set theory improves the modeling of real world, becoming a committing tool to deal with imprecise knowledge. In addition to vague implementation, second aim is to improve the performance of priority scheduling algorithm. In this paper we are proposing a new 2-stage scheduler with VOPS (vague oriented priority scheduling) algorithm. Proposed CPU Scheduler works in two stages; for the
%U http://www.hindawi.com/journals/afs/2014/841976/