1) Consider the following set of processes, with the length of the CPU burst time given in milliseconds:

Process Burst Time Priority (low numbers have a higher priority)

P1 9 5

P2 2 1

P3 7 1

P4 3 9

P5 6 6

The processes are assumed to have arrived in the order P1, P2, P3, P4, P5, all at time 0.

a. Draw four Gantt charts that illustrate the execution of these processes using the following scheduling algorithms: FCFS, SJF, nonpreemptive priority (a smaller priority number implies a higher priority), and RR (quantum = 2).

b. What is the turnaround time of each process for each of the scheduling algorithms in part a?

c. What is the waiting time of each process for each of these scheduling algorithms?

d. Which of the algorithms results in the minimum average waiting time (over all processes)?

2) The following processes are being scheduled using a preemptive, roundrobin 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.

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?

Thread Priority Burst Arrival

P1 20 30 0

P2 30 20 25

P3 30 15 40

P4 25 15 70

P5 5 10 90

P6 40 5 105

3) The following processes are being scheduled using a preemptive, roundrobin 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 5 units. If a process is preempted by a higher-priority process, the preempted process is placed at the end of the queue.

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?

Thread Priority Burst Arrival

P1 30 20 0

P2 20 15 10

P3 20 15 30

P4 40 30 60

P5 5 15 90

P6 10 10 105

Please do it step by step and write numbers for each step please as soon as possible?