CS 3733 Operating Systems, Spring 2000 Special Assignment 1
Due Friday, February 11, 2000, not to be handed in
Consider two processes, each with two CPU bursts with
one I/O burst in between.
Process 0 has a CPU burst of 8 units followed by an I/O burst of 3 units
and a CPU burst of 5 units.
Process 1 has a CPU burst of 5 units followed by an I/O burst of 8 units
and a CPU burst of 20 units.
Suppose that Process 0 arrives in the ready queue just before Process 1
and just after Process 1 arrives the process that was in the CPU terminates.
No other processes are in the system.
For each of the scheduling algorithms below, draw a Gantt chart
showing the CPU usage of the two processes and calculate the average waiting
time.
Be careful to take into account the I/O bursts of the processes
in calculating waiting time.
Which algorithm gives the best average waiting time?
a) First-Come/First-Served
b) Shortest Job First (non-preemptive)
c) Round Robin with a quantum of 5.