Application of Queueing Theory in CPU Scheduling Tapasvi Soni Kinjal Dhaduk
CPU scheduling is the technique in which processes in the ready queue are scheduled to get service from CPU. The concepts of queueing theory can be applied to improve the efficiency of scheduling algorithms and reduce response time and waiting time. The scheduling techniques may differ in terms of the amount of CPU service received by them. The service distribution for FCFS (First Come-First Served) and FEEDBACK(FB) scheduling is assumed to follow polynomial distribution whereas Round Robin(RR) scheduling is assumed to follow exponential service distribution.
Key Words and Phrases: Queueing theory, CPU scheduling, FCFS, FB , RR, Waiting Time, Response…show more content… On receiving service, customers depart out from the system. Different service disciplines are used such as FIFO, LIFO or Random Service order. In this paper, we choose a model that represents the behaviour of how processes get executed. As shown in figure the new processes arriving enter into the queue. If the central processing unit (CPU) is free then process get service for the fix time quantum. If the CPU is busy then process waits in the queue until CPU becomes free. If process executed during this quantum period of time it depart the system otherwise it is cycled back to the system of queue and wait there until it next chosen for additional service. The system of queue may select the process who receives the next time quantum by using various criteria. Here we used the criteria on the basis of total service so far received by the process. In order to use the queueing theory for scheduling, following criteria are considered. Process Inter Arrival Time Distribution: Time between arrivals of consecutive…show more content… Analysis of time-shared processor. Naval Res, Logostics Quarl. 2, 1(March 1964), 59-73. MCKINNEY, J.M. A survey of analytical time sharing models. Comput. Surv. 1, 2 (June 1969), 105-116. TAKACS, L. A single – server queue with feedback. Bell System Tech. J. 42(March 1963), 505-519. KLEINROCK, L. Time-shared systems: A theoretical treatment. J.ACM 14, 2(Apr. 1967), 242-261. COFFMAN, E.G., AND KLEINROCK, L. Feedback queueing models for time-shared systems. J.ACM 15, 4(Oct. 1968), 549-576. COFFMAN, E.G., JR., AND MUNTZ, R. R., AND TROTTER, H. Waiting time distributions for processor-sharing systems. J. ACM 17, 1(Jan. 1970), 123-130. KLEINROCK, L. AND COFFMAN, E.G. Distribution of attained service in time-shared systems. J. Comput. Sysems Sci.S (Oct 1967), 287-298. SAKATA, M., NOGUCHI, S., AND OIZUMI, J. Analysis of a processor for time-sharing systems. Proc. 2nd Hawaii Internat. Conf. on System Sciences, Jan. 1969, pp. 625-628. SCHRAGE, L. E. The queue M/G/1 with feedback to lower priority queues. Manag. Sci. 13, 7(19967), 466-471 CONWAY, R. W., MAXWELL, W, W., AND MILLER, L.W. Theory of scheduling. Addition-Wesley, Reading, Mass.,