Question

What are the three types of processor scheduling?

What is the difference between turnaround time and response time?

What is the difference between preemptive and non-preemptive scheduling?

Is a non-preemptive scheduling approach a good choice for interactive systems? Why?

What is the meaning of the term: feedback scheduling?

Answer 1

ANSWERS :

ANS 1. The 3 types of processor scheduler are :

a) Long term - also called job scheduler. It mainly offers a mix variety of jobs.

b) Short term - also called CPU scheduler. It mainly increases the system performance.

c) Medium term - also called swapping scheduler. It offers maximum speed among all the scheduler.

ANS 2. Difference between turnaround time and response time :

- Turnaround time is the time between the submission of job to the completion of the job.

- The Response time is the time between the submission to the first response.

  

ANS 3. Difference between preemptive and non-preemptive scheduling :

- Preemptive scheduling is the one in which the CPU preempt a low priority process whenever a high priority process comes into the queue or in the ready state. CPU is allocated to the process for a certain amount of time

- Non- preemptive scheduling is the one in which a process cannot be preempted until and unless it is completed. CPU is allocated to the process until it end's .

ANS 4. No, a non- preemptive scheduling is not a good approach for interactive systems .

This is because usually interactive systems uses round robin scheduling that is a type of preemptive scheduling. As it poses many Benifits that includes :

- improves the average response time.

- There is no starvation for any process.

- there is fair allocation of CPU to all the process.

These all Benifits are provided by only preemptive scheduling so this non preemptive will not provide these benifits and thus is not a good approach.

ANS 5. Feedback Scheduling : in this Scheduling the processes can move in between the queues. It is flexible and the benefit of this scheduling is mostly that in this different processes are separated with respect to the CPU burst time. This scheduling reduces the aging and starvation problem to large extent.