Linux operating system overview

Q1. What is GNU? What is the relationship between Linux and GNU?

A:

1) GNU is a recursive acronym for GNU is Not Unix, a project of the Free Software Foundation (FSF) that has developed many high quality Programming tools, including the emacs editor, the famous GNU C and C++ compilers (gcc and g++);

2) Linux development uses many GNU tools for implementing the POSIX.2 standard on Linux systems. The tools are almost all developed by the GNU project; the Linux kernel, GNU tools, and other free software make up what people often say about Linux or Linux distributions.

Q2. What are the components of the Linux system? Where is the Linux kernel located?

A:

1) The Linux system consists of four parts: user process, system call interface, Linux kernel subsystem and hardware;

2) Linux kernel is in the user Between process and hardware, including system call interface and Linux kernel subsystem.

Q3. What are the components of the Linux kernel? What are the main functions of each subsystem?

A:

1) In addition to system calls, the Linux kernel consists of five main subsystems: process scheduling, memory management, virtual file system, network, and interprocess communication (IPC). ;

2) The main functions of each subsystem are:

A. Process scheduling: It controls the access of the process to the CPU. When it is necessary to select a process to start running, it is selected by the scheduler. The most should be running;

B. Memory Management: It allows multiple processes to safely share the main memory area, supporting virtual memory; logically can be divided into hardware-independent parts and hardware-related parts; Br>

C. Virtual File System (VFS): It hides the specifics of various hardware, provides a unified interface for all devices, supports up to dozens of different file systems, and is divided into logical file systems and Device driver;

D. Network: It provides access to various network standard protocols and various network hardware support, divided into two parts: network protocol and network driver;

E. Interprocess communication: support between processes Communication mechanisms, including shared memory, message queues and pipes.