Implement the following CPU scheduling algorithms (FCFS and MLFQ) using any language Simulate and evaluate each with the set of processes below: 1. FCFS non preemptive 2. MLFQ

Multilevel Feedback Queue (preemptive absolute priority in higher queues) Queue 1 uses RR scheduling with Tq = 6 Queue 2 uses RR scheduling with Tq = 12 Queue 3 uses FCFS

All processes enter first queue 1. If time quantum (Tq) expires before CPU burst is complete, the process is downgraded to next lower priority queue. Processes are not downgraded when preempted by a higher queue level process. Once a process has been downgraded, it will not be upgraded.

Assumptions: 1. All processes are activated at time 0 2. Assume that no process waits on I/O devices. 3. After completing an I/O event, a process is transferred to the ready queue. 4. Waiting time is accumulated while a process waits in the ready queue.

5. Keep in mind that after all processes go through their first cpu burst they need to re-enter the ready queue in order of arrival time (this is for FCFS)

Process Data: process goes

{CPU burst, I/O time, CPU burst, I/O time, CPU burst, I/O time,.., last CPU burst} P1 { 4, 15, 5, 31, 6, 26, 7, 24, 6, 41, 4, 51, 5, 16, 4}

P2 { 9, 28, 11, 22, 15, 21, 12, 28, 8, 34, 11, 34, 9, 29, 10, 31, 7}

P3 { 24, 28, 12, 21, 6, 27, 17, 21, 11, 54, 22, 31, 18}

P4 { 15, 35, 14, 41, 16, 45, 18, 51, 14, 61, 13, 54, 16, 61, 15}

P5 { 6, 22, 5, 21, 15, 31, 4, 26, 7, 31, 4, 18, 6, 21, 10, 33, 3}

P6 { 22, 38, 27, 41, 25, 29, 11, 26, 19, 32, 18, 22, 6, 26, 6}

P7 { 4, 36, 7, 31, 6, 32, 5, 41, 4, 42, 7, 39, 6, 33, 5, 34, 6, 21, 9}

P8 { 5, 14, 4, 33, 6, 31, 4, 31, 6, 27, 5, 21, 4, 19, 6, 11, 6}

Example of output. (Results may differ this is just an example of the output)

Current Time: 0

Now running: P1 ..................................................

Ready Queue: Process Burst P2 9 P3 24 P4 15 P5 6 P6 22 P7 4 P8 5 ..................................................

Now in I/O: Process Remaining I/O time [empty]

::::::::::::::::::::::::::::::::::::::::::::::::::

Current Time: 4

Now running: P2 ..................................................

Ready Queue: Process Burst P3 24 P4 15 P5 6 P6 22 P7 4 P8 5 ..................................................

Now in I/O: Process Remaining I/O time P1 15

::::::::::::::::::::::::::::::::::::::::::::::::::

.

.

Current Time: 711

Now running: [idle] ..................................................

Ready Queue: Process Burst [empty] ..................................................

Now in I/O: Process Remaining I/O time P6 26 ..................................................

Completed: P1, P2, P3, P4, P5, P7, P8

::::::::::::::::::::::::::::::::::::::::::::::::::

Current Time: 737

Now running: P6 ..................................................

Ready Queue: Process Burst [empty] ..................................................

Now in I/O: Process Remaining I/O time [empty] ..................................................

Completed: P1, P2, P3, P4, P5, P7, P8

::::::::::::::::::::::::::::::::::::::::::::::::::

Current Time: 743

Now running: [idle] ..................................................

Ready Queue: Process Burst [empty] ..................................................

Now in I/O: Process Remaining I/O time [empty] ..................................................

Completed: P1, P2, P3, P4, P5, P6, P7, P8

::::::::::::::::::::::::::::::::::::::::::::::::::

Finished

Total Time: 743 CPU Utilization: 89.2328%

Waiting Times P1 P2 P3 P4 P5 P6 P7 P8 43 105 373 178 122 395 98 85 Average Wait: 174.875

Turnaround Times P1 P2 P3 P4 P5 P6 P7 P8 288 424 665 647 385 743 466 318 Average Turnaround: 492

Response Times P1 P2 P3 P4 P5 P6 P7 P8 0 24 343 37 13 225 4 8 Average Response: 81.75