Question

What are the pros and cons of each of the following scheduling algorithms: FCFS, RR, and SJF?

Answer 1

Answer:

FCFS:Which ever the process entered into the queue that will be executed.

pros:

Easy to implement.It is non-preemptive.First come first served.

cons:If the first entered process takes long time for execution.Then the other processes need to suffer from starvation.

Throughput is not efficient.There is less interactive with processes.

SJF:Shorted job first.Which ever processes has the least burst time that will be executed first.

Pros:We can execute more number of jobs in a very short period of time.We can achieve more throughput.

Cons:Time taken by a process should be know to the C.P.U Practically that won't be possible.We can't tell the burst time of a program Before it gets executed.

The long process has to be suffer from starvation though they arrive at the queue early.

RR:

pros:In round robin approach.Each process gets executed by the C.PU for a fixed time quantum.So every process get a chance to execute irrespective of their burst time and arrival times.No process suffer from starvation.

Cons:Throughput mainly depends upon on the length of the time quantum.If the time quantum is very less then the C.P.U has to perform more number of context switches.This reduces the c.p.u throughput.C.P.U time is wasted for context switches.

This effects the c.p.u efficiency.

Thank you...