Q. UGC NET 2015
An LRU page replacement is used with 4 page frames and eight pages. How many page faults will occur with the reference string 0 1 7 2 3 2 7 1 0 3 if the four frames are initially empty?
A. 6 B. 7 C. 5 D. 8
You should know:
Before seeing the solution please follow the previous chapter:
LRU page replacement algorithm.
Solution and explanation:
Given page references: 0, 1, 7, 2, 3, 2, 7, 1, 0, and 3.
The number of page faults is 7.
Shortcut method:
But in examination it is not possible to solve it by this elaborative way we can do it by a single frame like below:
Page references: 0, 1, 7, 2, 3, 2, 7, 1, 0, 3.
The above process is a shortcut and the easiest process to calculate page faults.
So, the number of page faults = 7.
Option B is correct.