《Operating System Concepts》阅读笔记：p359-p388

《Operating System Concepts》学习第 32 天，p359-p388 总结，总计 30 页。

一、技术总结

1.paging

(1)定义

A common memory management scheme that avoids external fragmentation by splitting physical memory into fixed-sized frames and logical memory into blocks of the same size called pages.

(2)frame & page

The basic method for implementing paging involves breaking physical memory into fixed-sized blocks called frames and breaking logical memory into blocks of the same size called pages.

2.getconf

getconf - get configuration value。

(1)查看 page size

# getconf PAGESIZE

4096

3.structure of page table

(1) hierarchical page

(2)hashed page table

(3)inverted page table

4.swapping

(1)定义

Moving a process between main memory and a backing store. A process may be swapped out to free main memory temporarily and then swapped back in to continue execution.

二、英语总结(生词：3)

1.leftover

(1)leftover: left("to allow to remain") + over("beyond")

adj. remaining, not used up(剩下的)； c. sth left over(残存物，遗留物)。

(2)示例

Which is the leftover piece—the one on the top or the one on the bottom?(《Operating System Concepts》第 359 页)。

2.nanosecond

(1)nanosecond: nano-(“a dwarf”) + second("a unit of time")

c.one-billionth (10⁻⁹) second。感觉这些单位都不好记。

3.oversubscribe

(1)oversubscribed: over("beyond") + subscribe + -ed

adj. applied for in greater quantities than are available(超额订阅).

(2)示例

The advantage of standard swapping is that it allows physical memory to be oversubscribed, so that the system can accommodate more processes than there is actual physical memory to store them(《Operating System Concepts》第 377 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 9 章(Main memeory)简评：介绍 paging。

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

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