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update words.md, modify something in lab2_report.md.

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Shine wOng
2019-11-19 08:35:31 +08:00
parent 1abf1ca4ff
commit b107db4c97
2 changed files with 107 additions and 5 deletions
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8
thu_os/lab2_report.md
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@@ -253,17 +253,17 @@ page_init(void) {
/* *
* Physical memory map:
*
* +---------------------------------+
* +---------------------------------+
* | |
* | Free Memory (*) |
* | |
* freemem -------------> +---------------------------------+
* | Struct Page *pages |
* | Struct Page *pages |
* pages ---------------> +---------------------------------+
* | Invalid Memory (*) |
* end kern ------------> +---------------------------------+
* | |
* | KERNEL |
* | KERNEL |
* | |
* load addr -----------> +---------------------------------+ 0x00100000
* | |
@@ -423,7 +423,7 @@ default_free_pages(struct Page *base, size_t n) {
}
```
在主循环里面，我是试图查找新加入的页面的后继页面，将新的页面插入到其后继页面之前，再进行合并的检测。但如果新加入页面是被插入到`free_area`链表的最后，则没有这样的后继页面，同时也只有可能与它的前驱进行合并了，`while`循环之后就是对于这种特殊情况的处理。相对于参考答案的代码，我的版本应该是更好的，因为参考答案用了两次循环，存在大量的冗余操作，当然老师的注释也写了应该对这个代码进行优化。
在主循环里面，我是试图查找新加入的页面的后继页面，将新的页面插入到其后继页面之前，再进行合并的检测。但如果新加入页面是被插入到`free_area`链表的最后，则没有这样的后继页面，同时也只有可能与它的前驱进行合并了，`while`循环之后就是对于这种特殊情况的处理。相对于参考答案的代码，我的版本应该是更好的，因为参考答案用了两次循环，存在大量的冗余操作，当然老师的注释也写了应该对这个代码进行优化。但是不管怎么样，我的这个代码还是存在太多冗余了，存在改进的余地（但是我懒得改了），以下简单说明以下：首先定位待插入页面的前驱`front`，如果`le2page(front) != free_list && front + front->property == base`，则更新`front`的信息，并且令`base = front`；否则插入`base`页面。无论哪种情况，以下再以`base`为基，判断后面的页面是否也可以合并。这样写性能不会更快，但是代码会简练不少。
## 页表的建立

104
words.md
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@@ -1801,5 +1801,107 @@ Some Words
- The package deal under discussion will require every country to be flexible on its immigration laws.
- Many small hotels offer accommodation and breakfast as a package deal.
+
## 18, November
+ justify
> (v)to show that something is reasonable, right or true.
- Her fears of a low voter turnout were justified when fewer than half of the people voted.
- She said that there was no justification for such a rude behaviour.
+ turnout
> (n)the number of people who are present at an event, especially the number who go to vote at an election.
- Good weather on polling day should ensure a good turnout.
+ dim
> (adj)not very clever
- He's a nice guy, but a little dim.
+ corporate
> (adj)relating to a business, especially a large business.</br>
> Corporate America: used to refer to large companies that have a lot of influence in the economy of the US.
- Analysts are expecting share prices to fall in the first quarter of next year because of poor corporate earnings.
+ put sb on notice
> (v)to warn someone offically that something is going to happen, or could possibly happen.
- The facility was put on notice that its funding was in danger if improvements were not carried out.
+ compliance
> (n)the act of obeying an order, rule or request.
- It is the job of the inspectors to enforce compliance with the regulations.
- We've been working hard to remain in compliance with all air pollution control laws.
+ feeble
> (adj)weak and without energy, strength or power.
- He was a feeble, helpless old man.
- Opposition to the plan was rather feeble.
- a feeble joke/excuse
+ pink slip
> (n)a document given to an employee to tell them that they do not have a job any longer.
- Eastern Airlines shut down operations at midnight, and 18,000 employees were given their pink slips.
+ outlive
> (v)to live or exist longer than someone or something.
- He outlived all of his brothers.
+ deductible
> (adj)a deductible expense is a cost that you can subtract from the earnings on which you have to pay income tax.</br>
> (n)a part of the cost of an accident, injury etc that you agree to pay yourself when you buy insurance.
- Customers can lower insurance premiums by taking higher deductibles.
+ odds
> (n)the probability that a particular thing will or will not happen.
- If you drive a car all your life, the odds are that you'll have an accident at some point.
+ attendant
> (adj)coming with a stated thing or resulting from it.
- debt and its attendant problems
- There are too many risks attendant on such a large investment of money.
+ eightfold
> (adj, adv)eight times as big or as much
- an eightfold increase
- Drug-related crimes jumped eightfold.
+ elude
> (v)if something that you want eludes you, you do not succeed in achieving it.</br>
> (v)if a piece of information eludes you, you cannot remember it.</br>
> (v)if you elude someone or something, you avoid them or escape from them.
- Sleep eluded her.
- They had minor breakthroughs but real success eluded them.
- I know who you mean but her name eludes me.
- He eluded the police for 13 years.
+ encompass
> (v)to include different types of things.
- The festival is to encompass everything from music, theatre and ballet to literature, cinema and the visual arts.
+ chronological
> (adj)following the order in which a series of events happened
- Give me the dates in chronological order.
- I have arranged these stories in chronological order.
- The exhibition is organized chronologically.
+ toil
> (v)to work hard</br>
> (n)hard work, especially work that makes you feel physically tired.
- People who toiled in dim factores were too exhausted to enjoy their family life.
- Well, after a day's toil in the office I like to relax a little.