Dr. M. RAJA SEKARProfessor, CSE Department, VNRVJIET, Hyderabad, India.
Optimization of the mixed model processor scheduling (OMMPS) is nothing but allocating the processor time to the number of process using mixed model of processor scheduling (MMPS) and minimizing the average turnaround time of process. Usually round robin scheduling and priority scheduling are taken into account with multilevel queue scheduling and and new scheduling concept is designed in which round robin scheduling consists of shortest job first. In the first level queue dead line scheduling is implemented. All the processes, which is ready to execute, must enter in to the ready queue. After entering in to the ready queue normally FIFO scheduling is used in round robin scheduling. Instead of FIFO we have also used priority scheduling in which the highest priority is given to the shortest processes and shortest are entering into the queue first. The nicety of this paper is that we have considered dead line scheduling in parallel with round robin (RR) scheduling in order to provide the execution of real time processes also. But we are not away from the concept of round robin scheduling. In round robin scheduling the hard part is deciding what the length of the time slice could be. This hard part is deciding what the length of the time slice could be. This hard part can be overcome by assuming the processes follows normal distribution with mean m and variance s2 and the time slice of each process is seal of s. Optimization of the mixed model processor scheduling consists of two queues namely q1 and q2. Where q1 is meant for real time processes and q2 consists of remaining processes in which shortest process are executed using normal dead line scheduling. Round robin scheduling is implemented for q2. The mentioned model applied for randomly various set of processes and shown that their average turnaround time is reduced comparatively with the usual pattern of round-robin scheduling and average waiting time can also be reduced.