《Operating System Concepts》阅读笔记：p17-p25

《Operating System Concepts》学习第 5 天，p17-p25 总结，总计 9 页。

一、技术总结

1.计算机系统的组成结构

(1)CPU—The hardware that executes instructions.

(2)Processor—A physical chip that contains one or more CPUs.

(3)Core—The basic computation unit of the CPU.

(4)Multicore—Including multiple computing cores on the same CPU.

(5)Multiprocessor—Including multiple processors.

本人觉得这写总结非常好，摘录一下。

2.dual-mode

In order to ensure the proper execution of the system, we must be able to distinguish between the execution of operating-system code and user-defined code. The approach taken by most computer systems is to provide hardware support that allows differentiation among various modes of execution(为了确保系统正确执行，我们要区分出某个执行是系统代码的执行还是用户代码的执行——大部分计算机采用的方法是提供硬件支持，允许在各种模式之间进行切换)。

(1)user mode

(2)kernel mode

也称为 supervisor mode, system mode, privileged mode。