Operating system FIFO页面替换是如何工作的？

我试图理解FIFO页面替换算法，但我能找到的所有信息都是下面的内容。您能否解释一下如何使用引用字符串来评估页面替换算法（使用FIFO的特定示例）

当必须替换页面时，将选择最旧的页面

在我们所有的示例中，引用字符串是

1, 2, 3, 4, 1, 2, 5, 1, 2, 3, 4, 5 3帧（9页错误） 4帧（10页错误）

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页面在队列中不可用时被替换

转到此链接

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这里解释了所有页面的重新定位算法。很好的例子。您很容易理解。

页面错误是指内存帧中不存在页面，因此必须向操作系统发送陷阱 页面必须添加到一个框架中。如果没有空间，那么需要移除一些东西。 FIFO是确定将删除哪个页面的一种方法

其概念是，首先添加到框架中的任何页面都将首先被删除。这就是FIFO的含义。使用您的第一个示例。我将进入引用字符串列表，并向您展示内存的外观

1:  1      +1 fault
2:  1,2    +1 fault
3:  1,2,3  +1 fault
4:  2,3,4  +1 fault - 1 gets removed because it was the first added
1:  3,4,1  +1 fault - 2 gets removed because it was the first on the list
2:  4,1,2  +1 fault - 3 got removed..
5:  1,2,5  +1 fault - 4 got removed..
1:  1,2,5  No change - 1 is already present so no page fault was required
2:  1,2,5  No change - 2 is already present in the frame
3:  2,5,3  +1 fault - 1 was removed because it is first
4:  5,3,4  +1 fault - Now 2 got removed
5:  5,3,4  No change - No change because 5 is present in one of the frames.

这总共给出了9个故障

您还可以将其视为最旧的页面被删除

希望我没有犯错误：D

--------------先进先出*-------------

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这个问题永远不会过时！

Page no. 1 |   1 +1

Page no. 2 |   1 2 +1

Page no. 3 |   1 2 3 +1

Page no. 4 |   1 2 3 4 +1

Page no. 1 |  

Page no. 2 |  

Page no. 5 |   2 3 4 5 +1

Page no. 1 |   3 4 5 1 +1

Page no. 2 |   4 5 1 2 +1

Page no. 3 |   5 1 2 3 +1

Page no. 4 |   1 2 3 4 +1

Page no. 5 |   2 3 4 5 +1


Page Faults = 10

1:  1      +1 fault
2:  1,2    +1 fault
3:  1,2,3  +1 fault
4:  2,3,4  +1 fault - 1 gets removed because it was the first added
1:  3,4,1  +1 fault - 2 gets removed because it was the first on the list
2:  4,1,2  +1 fault - 3 got removed..
5:  1,2,5  +1 fault - 1 got removed..
1:  1,2,5  No change - 1 is already present so no page fault was required
2:  1,2,5  No change - 2 is already present in the frame
3:  2,5,3  +1 fault - 1 was removed because it is first
4:  5,3,4  +1 fault - Now 2 got removed
5:  5,3,4  No change - No change because 5 is present in one of the frames.