Interview Questions on OS - Cpu Scheduler

1. What are all the scheduling algorithms?

1. FCFS(FirstCome First Serve)
2. SJF(Shortest Job First)
3. Round robin
4. Priority Scheduling algorithms

2. Explain FCFS(First Come First Served)?

The process that requests the CPU first is allocated the CPU first. The code for FCFS scheduling is simple to write and understand.

3. Explain SJF(Shortest Job First)?

The process which has the less burst time execute first. If both process have same burst time then FCFS will be used.

4. Explain Round Robin?

The round-robin (RR) scheduling algorithm is designed especially for timesharing systems. CPU switch between the processes based on a small unit of time called time slice.

5. Explain Priority Scheduling algorithm?

CPU is allocated to the process with the highest priority.

6. Which algorithm gives minimum average waiting time?

SJF(Shortest Job First)

7. What is CPU utilization?

We want to keep the CPU as busy as possible. Conceptually, CPU utilization can range from 0 to 100 percent. In a real system, it should range from 40 percent (for a lightly loaded system) to 90 percent.

8. What is Throughput?

The amount of work is being done by the CPU. One unit of work is the number of processes that are completed per unit time, called throughput

9. What is Turnaround time.

The interval from the time of submission of a process to the time of completion is the turnaround time

10. What is waiting time?

Waiting time is the sum of the periods spent waiting in the ready queue.

11. What is Response time?

the time from the submission of a request until the first response is produced.