51.设进程分得三个页框,其执行访问序列为:0,1,2,3,0,1,2,3,0,1,2,3,4,5,6,7。试采用:(1)Belady;(2)LRU;(3)LFU;(4)FIFO算法,来分别计算缺页异常次数,并给出缺页时加进内存的页号。
时间: 2023-07-14 11:14:19 浏览: 44
假设物理内存有3个页框。
(1)Belady算法:
| 页面 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | | | | 0 | | | | 0 | | | | 0 | | | |
| 1 | 0 | 1 | | | 0 | 1 | | | 0 | 1 | | | 0 | 1 | | |
| 2 | 0 | 1 | 2 | | 0 | 1 | 2 | | 0 | 1 | 2 | | 0 | 1 | 2 | |
| 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 |
| 4 | | 1 | 2 | 3 | 4 | 1 | 2 | 3 | 4 | 1 | 2 | 3 | 0 | 1 | 2 | 3 |
| 5 | | | 2 | 3 | 4 | 5 | 2 | 3 | 4 | 5 | 2 | 3 | 0 | 1 | 2 | 3 |
| 6 | | | | 3 | 4 | 5 | 6 | 3 | 4 | 5 | 6 | 3 | 0 | 1 | 2 | 3 |
| 7 | | | | | 4 | 5 | 6 | 7 | 4 | 5 | 6 | 7 | 4 | 5 | 2 | 3 |
|缺页数| 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 4 |
缺页异常次数为4,加进内存的页号分别为0,1,2,3,4,5,6,7。
(2)LRU算法:
| 页面 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | | | | 0 | | | | 0 | | | | 0 | | | |
| 1 | 0 | 1 | | | 0 | 1 | | | 0 | 1 | | | 0 | 1 | | |
| 2 | 0 | 1 | 2 | | 0 | 1 | 2 | | 0 | 1 | 2 | | 0 | 1 | 2 | |
| 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 |
| 4 | | 1 | 2 | 3 | 4 | 1 | 2 | 3 | 4 | 1 | 2 | 3 | 4 | 1 | 2 | 3 |
| 5 | | | 2 | 3 | 4 | 5 | 2 | 3 | 4 | 5 | 2 | 3 | 4 | 5 | 2 | 3 |
| 6 | | | | 3 | 4 | 5 | 6 | 3 | 4 | 5 | 6 | 3 | 4 | 5 | 6 | 3 |
| 7 | | | | | 4 | 5 | 6 | 7 | 4 | 5 | 6 | 7 | 4 | 5 | 6 | 7 |
|缺页数| 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 4 |
缺页异常次数为4,加进内存的页号分别为0,1,2,3,4,5,6,7。
(3)LFU算法:
| 页面 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | | | | 0 | | | | 0 | | | | 0 | | | |
| 1 | 0 | 1 | | | 0 | 1 | | | 0 | 1 | | | 0 | 1 | | |
| 2 | 0 | 1 | 2 | | 0 | 1 | 2 | | 0 | 1 | 2 | | 0 | 1 | 2 | |
| 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 |
| 4 | | 1 | 2 | 3 | 4 | 1 | 2 | 3 | 4 | 1 | 2 | 3 | 0 | 4 | 2 | 3 |
| 5 | | | 2 | 3 | 4 | 5 | 2 | 3 | 4 | 5 | 2 | 3 | 0 | 4 | 2 | 3 |
| 6 | | | | 3 | 4 | 5 | 6 | 3 | 4 | 5 | 6 | 3 | 0 | 4 | 2 | 3 |
| 7 | | | | | 4 | 5 | 6 | 7 | 4 | 5 | 6 | 7 | 4 | 5 | 2 | 3 |
|缺页数| 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 4 | 5 | 5 | 5 |
缺页异常次数为5,加进内存的页号分别为0,1,2,3,4,5,6,7。
(4)FIFO算法:
| 页面 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 |
|------|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | | | | 0 | | | | 0 | | | | 0 | | | |
| 1 | 0 | 1 | | | 0 | 1 | | | 0 | 1 | | | 0 | 1 | | |
| 2 | 0 | 1 | 2 | | 0 | 1 | 2 | | 0 | 1 | 2 | | 0 | 1 | 2 | |
| 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 | 0 | 1 | 2 | 3 |
| 4 | | 1 | 2 | 3 | 4 | 1 | 2 | 3 | 4 | 1 | 2 | 3 | 4 | 1 | 2 | 3 |
| 5 | | | 2 | 3 | 4 | 5 | 2 | 3 | 4 | 5 | 2 | 3 | 4 | 5 | 2 | 3 |
| 6 | | | | 3 | 4 | 5 | 6 | 3 | 4 | 5 | 6 | 3 | 4 | 5 | 6 | 3 |
| 7 | | | | | 4 | 5 | 6 | 7 | 4 | 5 | 6 | 7 | 4 | 5 | 6 | 7 |
|缺页数| 1 | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 3 | 3 | 3 | 3 | 4 | 4 | 4 | 4 |
缺页异常次数为4,加进内存的页号分别为0,1,2,3,4,5,6,7。