Operating-System-Concepts阅读笔记p208-p227
《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 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：
(2) Cambridge Dictionary：
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