Question

The following processes are being scheduled using a preemptive, round-robin scheduling algorithm. Each process is assigned a numerical priority, with a higher number indicating a higher relative priority. In addition to the processes listed below, the system also has an idle task (which consumes no CPU resources and is identified as Pidle). This task has priority 0 and is scheduled whenever the system has no other available processes to run. The length of a time quantum is 10 units. If a process is preempted by a higher-priority process, the preempted process is placed at the end of the queue.
Thread Priority Burst Arrival
P1 40 20 0
P2 30 25 25
P3 30 25 30
P4 35 15 60
P5 5 10 100
P6 10 10 105

a. Show the scheduling order of the processes using a Gantt chart.
b. What is the turnaround time for each process?
c. What is the waiting time for each process?
d. What is the CPU utilization rate?

Answer 1

Answer:

a) P1 P2 Pidle P2 P3 P2 P3 P4 P2 P3 Pidle P5 P6 P5

0 10 20 25 35 45 55 60 75 80 90 100 105 115 120

b,c) See attached picture.

d) 87.5%

Explanation:

See attached picture.