Explain the Features of Major scheduling algorithms (8) Ans: 1. FCFS – First come first served scheduling 2. Shortest job – First scheduling 3. Priority scheduling 4. Round robin scheduling FCFS- 1. Process that request the CPU first is allocated CPU first 2. Managed by FIFO queue. 3. Average waiting time is generally long 4. Non preemptive 5. Troublesome for time sharing systems Shortest job first 1. The process which has the smallest CPU burst time gets first 2. It increases the waiting time of long processes. 3. Problem – difficult to predict the length of next CPU request 4. May be preemptive or non preemptive Priority 1. Highest priority process gets CPU allocation first 2. The larger the CPU burst, lower the priority 3. Priority can be defined internally or externally 4. Can be preemptive or non-preemptive 5. Problem-starvation, blocking of process 6. Solution – aging – increases the priority1. Time quantum from 10 100 millisecond is defined 2. Processes are considered in circular queue 3. CPU allocation is divided among processes accordingly 4. Performance depends heavily on time quantum 5. Preemptive