Suppose we have the following page accesses: 1 2 3 4 2 3 4 1 2 1 1 3 1 4 and that there are three frames within our system. Using the FIFO replacement algorithm, what is the number of page faults for the given reference string?
A) 14
B) 8
C) 13
D) 10

Question

Quizplus · Accepted Answer

FIFO (First-In, First-Out) page replacement algorithm removes the oldest page in memory that was brought in first. For the given reference string and 3 frames, the process of page replacement goes as follows:1. Start with empty frames.2. Access pages in the order given: 1, 2, 3, 4, 2, 3, 4, 1, 2, 1, 1, 3, 1, 4.3. Each time a page needs to be loaded that isn't already in one of the frames, it's a page fault.- Initially, 1, 2, 3 are loaded into the frames (3 page faults).- 4 replaces 1 (1 page fault).- 2 and 3 are already in the frames, so no page faults occur.- 4 is already in the frame, so no page fault occurs.- 1 replaces 2 (1 page fault).- 2 replaces 3 (1 page fault).- 1 is already in the frame, so no page fault occurs.- 3 replaces 4 (1 page fault).- 1 is already in the frame, so no page fault occurs.- 4 replaces 2 (1 page fault).Total page faults = 3 (initial) + 1 (for 4) + 1 (for 1) + 1 (for 2) + 1 (for 3) + 1 (for 4) = 8.

Suppose We Have the Following Page Accesses: 1 2 3