我正在尝试了解 FIFO 页面替换算法，但我能找到的所有信息都属于以下内容。您能解释一下如何使用参考字符串来评估页面替换算法，使用 FIFO 的特定示例吗？
当必须替换页面时，将选择最旧的页面。
在我们所有的例子中，参考字符串是
1, 2, 3, 4, 1, 2, 5, 1, 2, 3, 4, 5
3 帧（9 个页面错误） 4 帧（10 个页面错误）
问问题
52633 次
4 回答
10
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并且必须将页面添加到帧中。如果没有空间，则需要移除某些东西。FIFO 是一种确定要删除哪个页面的方法。
这个概念是，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。使用你的第一个例子。我将查看参考字符串列表，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.
这给出了总共 9 个故障。
您也可以将其视为最旧的页面被删除。
希望我没有犯错：D
于 2013-11-09T22:35:21.910 回答
4
------------ * 先进先出 * -------------
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
于 2014-02-06T06:45:56.397 回答
3
于 2012-12-12T07:33:04.743 回答
-2
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.
于 2015-08-14T09:27:54.053 回答