GATE - 2012 | OS | Consider the virtual page reference string 1, 2, 3, 2, 4, 1, 3, 2, 4, 1 On a
Posted on 12-02-2022
GATE - 2012 [Operating System]
Question:
Consider the virtual page reference string 1, 2, 3, 2, 4, 1, 3, 2, 4, 1 On a demand paged virtual memory system running on a computer system that main memory size of 3 pages frames which are initially empty. Let LRU, FIFO and OPTIMAL denote the number of page faults under the corresponding page replacements policy. Then
|
A |
OPTIMAL < LRU < FIFO |
|
B |
OPTIMAL < FIFO < LRU |
|
C |
OPTIMAL = LRU |
|
D |
OPTIMAL = FIFO |
Solution:
Option (B) is Correct.
FIFO:
No. of page faults with FIFO = 6
LRU:
No. of page faults with LRU = 9
Optimal:
No. of page faults with optimal = 5
∴ Optimal < FIFO < LRU