IJITE Vol.03 Issue-06, (June, 2015) ISSN: 2321-1776 International Journal in IT and Engineering, Impact Factor- 4.747 A Monthly Double-Blind Peer Reviewed Refereed Open Access International e-Journal - Included in the International Serial Directories International Journal in IT and Engineering http://www.ijmr.net.in email id- irjmss@gmail.com Page 104 CPU SCHEDULING POLICIES USING FUZZY LINGUISTIC VARIABLES IN REAL WORLD ENVIRONMENT Jaspreet kaur*,Silky Miglani**T.P.Singh*** *Research scholar (CSE) Yamuna Institute of Engg. & Tech. Gadholi **Assistant Prof.Yamuna Institute of Engg. & Tech. Gadholi,Yamuna Nagar. ***Professor (Maths and Computer Science)Yamuna Institute of Engg. & Tech. Gadholi,Yamuna Nagar. ABSTRACT The performance of CPU depends on the scheduling policies adopted. These policies provide a schedule framework for execution of processes waiting in ready queue. Various scheduling algorithms as FCFS, SJF, Priority, Round Robin are already existing in the literature for operating system. In an interactive environment, these scheduling policies differ in their efficiency depending upon the characteristics and criteria to be considered .Fuzzy logic can be integrated to decide the task to be implemented according to sequential order. In the present paper, we propose the integration of fuzzy logic with existing Scheduling policies. Fuzzy logic concept is used to select among different values by using reasoning which is approximate and vague. By Fuzzy Logic we are able to decide on the basis of already known knowledge that in which order instructions are given by the user. The inference system in fuzzy logic enables the scheduler to invoke the order of task as in the beginning rather waiting for high and low priorities .In this paper we have designed a C++ simulator to compare various CPU parameters. With Linguistic variables introduced through Fuzzy Inference Rule , the efficiency of different scheduling policies have been evaluated. Keywords-Round Robin, Fuzzy logic, Ready Queue, Fuzzy Inference System. 1.INTRODUCTION The CPU Scheduling is one of the important research area of Operating System. It acts as a backbone in any computer system as it decides to allocate resources among different processes efficiently. Scheduling algorithms play an important role in computing systems as a means of meeting user demands as per number of processes. Various scheduling algorithms such as priority, FCFS, SJF, RR, etc. are available but none is sufficient for real time task. In FCFS algorithm, the shortcomings are throughput can be low since long processes can hold the CPU, secondly turnaround time, waiting time, response time can be high for the same reason no prioritization occurs as the system has trouble to meet deadlines. The SJF algorithm selects the process with lowest burst time but the shortcoming of the algorithm is that it is very difficult to know the burst time of next CPU request. Secondly, it cannot be implemented at the level of short term CPU Scheduling. In Priority scheduling algorithm, the process with highest priority is assigned CPU first and so on. The low priority process gets interrupted by incoming of higher priority. Hence creates indefinite blocking and starvation of lowest priority process due to large number of high priority. Round Robin algorithm has high context switching rates and less throughput along with large waiting time, response time and turn around time. The efficiency of Round Robin is totally depends on the Quantum. If the quanta is too small, every process executes for a small amount time which causes frequent context switching. This puts overhead over CPU. Further if Quanta is too large, the process executes for long duration and hence it maximize waiting time. These shortcomings can be improved by adding fuzzy logic as an inference of decision with FCFS, SJF, Priority and Efficient Round Robin. In this paper, we discuss scheduling policies under fuzzy inference system rule which better suits for a real time environment. 2.LITERATURE SURVEY Alexander[1999] stated that Multimedia applications have unique requirements that must be met by networks and operating system components. In context of multimedia applications, the CPU scheduler determines quality of service rendered. Efficient soft real-time processing is proposed by C. Lin et al[2004]. The more CPU cycles scheduled to a process, the more data can be produced faster ,which results in better quality ,more reliable output. Terry Regner & Craig Lacey[2005]