Scheduling

Question 1

Why is scheduling needed?

Answer 1

When multiprocessing, a system has to decide which process to run

Question 2

When is a scheduling decision needed?

Answer 2

When a process exits
When a process blocks on Input/Output (or waiting for a resource)

Question 3

Job AT RT
A 2 7
B 0 10
C 5 3
D 1 10
E 6 3

Work out the mean turnaround time using Shortest Remaining Time Next

Answer 3

A – 13, B- 23, C-3, D-32, E-5
Turnaround Time = 76/5 = 15.2

Question 4

Job AT RT
A 0 5
B 0 4
C 3 3
D 0 5
E 7 6

Work out the mean turnaround time using Round Robin

Answer 4

A – 20, B- 17, C-14 , D-20, E-16
Turnaround Time = 87/5 = 17.4

Question 5

Job AT RT
A 2 10
B 0 15
C 13 7
D 4 5
E 13 4

Work out the mean turnaround time using Shortest Remaining Time Next

Answer 5

A – 35, B- 41, C-26 , D-19, E-18
Turnaround Time = 139/5 = 27.8

Question 6

Job AT RT
A 0 1
B 0 5
C 2 2
D 2 3
E 4 1

Work out the mean turnaround time using Shortest Job First

Answer 6

A – 1, B- 6, C-7 , D-10, E-3
Turnaround Time = 139/5 = 5.4