Week 9 - Scheduling

Question 1

What is the main advantage of first come first served scheduling?

Answer 1

Easy to implement

Question 2

What is the main disadvantage of first come first served scheduling?

Answer 2

CPU intensive process can cause a long waiting time

Question 3

What is the main advantage of round robin scheduling?

Answer 3

Resources shared equally

Question 4

What is the main disadvantage of round robin scheduling?

Answer 4

Difficult to get the right time quantum(Too short means too much time wasted on context switches, too long and one process hogs the CPU)

Question 5

What is the main advantage of priority scheduling?

Answer 5

Ensures quick response time to high priority processes

Question 6

What is the main disadvantage of priority scheduling?

Answer 6

Low priority processes can have long wait times.

Question 7

How do you prevent low priority processes never being executed in priority scheduling?

Answer 7

Aging - Increasing the priority of waiting processes over time.

Question 8

What are the two main categories of processes?

Answer 8

I/O bound - requires many short CPU bursts
CPU bound - requires few very long CPU bursts

Question 9

What are the 5 criteria for successful scheduling?

Answer 9

CPU utilisation
Throughput – Number of processes completed within a given time
Turnaround time – Time it takes for each process to execute
Waiting time – Amount of time spent in the ready-queue
Response time – time between submission requests and production of first response