Consider the following page reference string, for a process with 5 virtual pages, and three frames in memory, and fill in the tables for the LRU.
When a page reference is not in the frames, we report a page fault with X, unless a frame is empty and the frame is filled with that page reference. When a page fault occurs, the page reference which was used least recently is replaced with the current page reference.
Page Reference | Frame 1 | Frame 2 | Frame 3 | Page Fault | Reason |
A | A | X | Since all frames are empty, We fill Frame 1 with A. | ||
B | A | B | X | Since two frames are empty, We fill Frame 2 with B. | |
C | A | B | C | X | Since one frame is empty, We fill Frame 3 with C. |
B | A | B | C | B is present in Frame 2, so no page fault. | |
D | D | B | C | X | Since A is referenced least recently compared to B and C, it is replaced with D. |
E | D | B | E | X | Since C is referenced least recently compared to B and D, it is replaced with E. |
A | D | A | E | X | Since B is referenced least recently compared to D and E, it is replaced with A. |
B | B | A | E | X | Since D is referenced least recently compared to A and E, it is replaced with B. |
C | B | A | C | X | Since E is referenced least recently compared to B and A, it is replaced with C. |
D | B | D | C | X | Since A is referenced least recently compared to B and C, it is replaced with D. |
A | A | D | C | X | Since B is referenced least recently compared to D and C, it is replaced with A. |
Total page faults is 10.
Consider the following page reference string, for a process with 5 virtual pages, and three frames...
Question 7 30 pts Consider the following page reference string: {1,2,3,4,1,5,6,2,1,2,3,7,6,3} Assume that the system has 4 page frames allocated to these 7 pages. Follow the page placement and replacement using the following three replacement algorithms: • LRU replacement • FIFO replacement • Optimal replacement How many page faults will occur for these three algorithms? Assume that all frames are initially empty, so your first unique pages will all cost one fault each USE ENCLOSED TABLES! Show all calculations in...
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