Question

consider following page references string: 7, 7, 1, 0, 8, 5, 8, 6, 2, 1, 0, 7, 0, 100 Assuming demand paging with four frames, how many page faults would occur for the following replacement algorithms? LRU replacement algorithm

Answer 1

Using the Least Recently Used (LRU) replacement algorithm with four frames, the provided page reference string would result in a total of 11 page faults.

Step-by-step explanation:

The question asks about the number of page faults that would occur using the Least Recently Used (LRU) replacement algorithm in a demand paging system with four frames, given a specific page reference string.

To answer this, we track page usage over time and evict the least recently used page when a new page must be loaded and there's no free frame available.

The page reference string is: 7, 7, 1, 0, 8, 5, 8, 6, 2, 1, 0, 7, 0, 100

Here's how the LRU algorithm would process this string with four frames:

1. Page 7 loaded (fault).
2. Page 7 requested (no fault).
3. Page 1 loaded (fault).
4. Page 0 loaded (fault).
5. Page 8 loaded (fault).
6. Page 5 loaded, 7 replaced (fault).
7. Page 8 requested (no fault).
8. Page 6 loaded, 1 replaced (fault).
9. Page 2 loaded, 0 replaced (fault).
10. Page 1 loaded, 8 replaced (fault).
11. Page 0 loaded, 5 replaced (fault).
12. Page 7 loaded, 6 replaced (fault).
13. Page 0 requested (no fault).
14. Page 100 loaded, 2 replaced (fault).

The LRU algorithm produces a total of 11 page faults for the given page reference string.