《Operating System Concepts》学习第 34 天，p408-p448 总结，总计 41 页。
一、技术总结
2.page-replacement algorithm
In memory management, the algorithm that chooses which victim frame of physical memory will be replaced by a needed new frame of data.
(1)FIFO pagte replacement
(2)optimal page replacement
(3)LRU page replacement
(4)LRU-Approxiation page replacement
(5)Counting-Base page replacement
2.thrashing
Paging memory at a high rate. A system thrashes when there is insufficient physical memory to meet virtual memory demand。
二、英语总结(生词：3)
1.approximation
(1)approximate: ad-(“to”) + proximus(“nearest”)
vi/vt. to be almost the same as. adj. not completely accurate but close(大概的).
(2)approximation: noun of action from approximate
c. a value that is nearly but not exactly correct.
(3)示例
Could you give me a rough approximation of how many people will be coming?
2.expansion
(1)expand: ex-(“out”) + pandere(“to spread, stretch”)
vi/vt. to increase in size, number or importance(扩大，增加)。
(2)expansion
c/u. the increase in size, number or importance(扩大，增加)。
(3)示例
An expansion of this idea is to maintain a list of modified pages(《Operating System Concepts》第 412 页)。
3.reaper
(1)reap
vi/vt. to cut and collect a grain crop(收割)。
(2)reaper
c. a machine that cut and collect crops(收割机)。
(3)示例
Such kernel routines are often known as reapers, and they may apply any of the page-replacement algorithms covered in Section 10.4(《Operating System Concepts》第 417 页)。
关于英语的注解同步更新汇总到 https://github.com/codists/English-In-CS-Books 仓库。
三、其它
第 10 章(Virtual Memory)简评：介绍虚拟内存相关的 demand paging, page-fault, page-replacement algorithm, 感觉真抽象啊。
四、参考资料
1. 编程
(1) Abraham Silberschatz，Peter Baer Galvin，Greg Gagne《Operating System Concepts》：https://book.douban.com/subject/30272539/
2. 英语
(1) Etymology Dictionary：https://www.etymonline.com
(2) Cambridge Dictionary：https://dictionary.cambridge.org
欢迎搜索及关注：编程人(a_codists)