《Operating System Concepts》学习第 25 天，p228-p257 总结，总计 30 页。

一、技术总结

1.algorithm evaluation

评估 CPU 调度算法需要考虑的因素有：CPU utilization, response time 或者 throughput。

基于以上几个因素，选择依据为：

(1)Maximizing CPU utilization under the constraint that the maximum response time is 300 milliseconds.

(2)Maximizing throughput such that turnaround time is (on average) linearly proportional to total execution time.

二、英语总结(生词：2)

1.monotonic

(1)monotonic: mono-("one, single, along") + tonic("relating to tone")

adj. 1.monotonic literally means speaking in such a way that the sounds stays on the same note without going higher or lower(单调的，这里主要指声音方面的)。2.varying in such a way that it either never decreases or never increases.

(2)示例

The rate-monotonic scheduling algorithm schedules periodic tasks using a static priority policy with preemption(《Operating System Concepts》第 230 页)。

2.processing

(1)adjective 用法

In fact, a process may be interrupted at any point in its instruction stream, and the processing core may be assigned to execute instructions of another process(《Operating System Concepts》第 257 页)。

在上面这个例子中，processing 用于修饰 core, 表示“ core is used for processing”。

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 5 章(CPU Scheduling)简评：介绍 CPU 调度：调度算法，算法评估。再次感叹，作者能把每个概念都介绍得清楚明了。

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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