《Operating System Concepts》阅读笔记：p208-p227

《Operating System Concepts》学习第 24 天，p208-p227 总结，总计 20 页。

一、技术总结

1.vmstat

Linux 系统上 vmstat 命令的作用是“Report virtual memory statistics”。

2.scheduling algorithms

(1)FCFS(first-come first-serve)

(2)SJF(shortest-job-first)

准确的叫法应该是“shortest-next-CPU-burst”。

(3)RR(Round-Robin Scheduling)

A scheduling algorithm similar to FCFS scheduling, but with preemption added to enable the system to switch between threads; designed especially for time-sharing systems.

(4)priority scheduling

A scheduling algorithm in which a priority is associated with each thread and the free CPU core is allocated to the thread with the highest priority.

(5)multilevel queue scheduling

A scheduling algorithm in which a priority is associated with each thread and the free CPU core is allocated to the thread with the highest priority.

(6)Multilevel Feedback Queue Scheduling

A scheduling algorithm that allows a process to move between queues.

3.load balancing

(1)定义

The movement of jobs or network packets between various components (say, computers in a network) to distribute the load or route around failures.

Load balancing attempts to keep the workload evenly distributed across all processors.

二、英语总结(生词：4)

1.feeback

(1) feedback: feed("give food to, supply") + back("return to a previous position")

c.information about reactions to sth, which is used as basis for improvement。

2.heterogeneous

(1)heterogeneous: hetero-("different") + *gene-("give birth, beget")

adj. consisting of different kinds.

3.affinity

(1)affinity: ad-("to") + finis("a border, a boundry", 参考 finish("to bring to an end"))

c/u. a natural connection(亲缘性), attraction(亲和力) or relationship(密切关系)。

语法结构：A have an affinity for/with B。

(2)示例

This is known as processor affinity—that is, a process has an affinity for the processor on which it is currently running(《Operating System Concepts》第 207 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

日拱一卒，功不唐捐。

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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