UGC NET CSE | July 2016 | Part 2 | Question: 36

Question

Consider the reference string:

0 1 2 3 0 1 4 0 1 2 3 4

If FIFO page replacement algorithm is used, then the number of page faults with three page frames and four page frames are ____ and ___ respectively.

• A. 10, 9
• B. 9, 9
• C. 10, 10
• D. 9, 10

Comments

THIS QUESTION IS THE PERFECT EXAMPLE OF Belady's Anomaly.............

Answer 1

For frame size =3

0 1 2 3 0 1 4 0 1 2 3 4

F F F F F F F H H F F H

Total 9 page fault

For Frame Size =4

0 1 2 3 0 1 4 0 1 2 3 4

F F F F H H F F F F F F

Total 10 page fault

So option D is Ans.

Comments

How you choosed  values like F F F F F F F H H F F H as per page frame size??