《Operating System Concepts》學習第 32 天，p359-p388 總結，總計 30 頁。

一、技術總結

1.paging

(1)定義

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)定義

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、英語總結(生詞：3)

1.leftover

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

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

(2)示例

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

2.nanosecond

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

c.one-billionth (10??) second。感覺這些單位都不好記。

3.oversubscribe

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

adj. applied for in greater quantities than are available(超額訂閱).

(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 頁)。

關于英語的注解同步更新匯總到 https://github.com/codists/English-In-CS-Books 倉庫。

三、其它

第 9 章(Main memeory)簡評：介紹 paging。

四、參考資料

1. 編程

(1) Abraham Silberschatz，Peter Baer Galvin，Greg Gagne《Operating System Concepts》：https://book.douban.com/subject/30272539/

2. 英語

(1) Etymology Dictionary：https://www.etymonline.com

(2) Cambridge Dictionary：https://dictionary.cambridge.org

歡迎搜索及關注：編程人(a_codists)