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This article mainly introduces "what are the functions of the Linux kernel". In the daily operation, I believe many people have doubts about the functions of the Linux kernel. The editor consulted all kinds of materials and sorted out simple and easy-to-use operation methods. I hope it will be helpful for you to answer the doubts about "what are the functions of the Linux kernel?" Next, please follow the editor to study!

01 preface

With more than 13 million lines of code, the Linux kernel is one of the largest open source projects in the world, but what is the Linux kernel and what is it used for? Just listen to us slowly.

02 what is the Linux kernel?

Linux kernel is the core of Linux operating system, which refers to a system core program maintained by Linus Torvalds, which provides hardware abstraction layer, hard disk and file system control and multitasking functions.

Linux operating system is a collection of Linux kernel and all kinds of commonly used software.

03 Linux kernel version naming rules

There are two versions of the Linux kernel: stable version and development version.

The Linux kernel version number consists of three numbers: r.x.y

R: the currently released major version of the kernel.

X: an even number indicates a stable version; an odd number indicates a version under development.

Y: the number of times the error was patched.

We execute uname-an on the mainframe

Uname-a: displays system name, node name, operating system distribution number, kernel version, and so on.

System name:

Linux

Node name:

Qll

Release number of the operating system:

3.10.0-1127.el7.x86_64

Naming rules:

Major version number: 3

Minor version number: 10 [odd number is development version, even number is stable version]

Revision number: 0 [number of modifications]

The Nth revision of this version: 1127

El7:redhat enterprise linux 7

X86room64: compilation framework (64-bit)

Kernel version:

# 1 SMP Tue Mar 31 23:36:51 UTC 2020

Hardware platform:

X86_64

Machine hardware name:

X86_64

Architecture of the system processor:

X86_64

Operating system:

GNU/Linux

Linux kernel version naming has different naming conventions in different periods, in 2.x version, if X is odd for development version, X for even number means stable version, from 2.6.x and 3.x, there is no strict convention for kernel version naming.

The main functions of 04 Linux kernel

The Linux kernel is the core of the whole Linux function. It is written in C language and conforms to the Posix standard.

The main functions of Linux kernel include process management, memory management, file management, device management, network management and so on.

Process management:

A process is the smallest unit of resource allocation in a computer system. The kernel is responsible for creating and destroying processes, and the scheduler adopts appropriate scheduling strategies to achieve reasonable and real-time processor resource sharing among processes. Thus, the process management activity of the kernel realizes the abstraction of multiple processes on one or more processors. The kernel is also responsible for implementing communication between different processes and between processes and other components.

Memory Management:

Memory is the main resource in computer system. The kernel enables multiple processes to share memory resources safely and reasonably, creating a virtual address space for each process on limited physical resources. The code of the memory management part can be divided into the hardware-independent part and the hardware-related part: the hardware-independent part realizes the address mapping between the process and memory; the hardware-related part implements the memory management-related functions on different architectures and provides hardware-independent virtual interfaces for memory management.

File Management:

Almost any concept in the Linux system can be seen as a file. The kernel establishes a structured virtual file system on unstructured hardware, hiding the specific details of all kinds of hardware, thus using file abstraction in almost all mechanisms of the whole system. Linux supports dozens of file systems on different physical media or virtual structures. For example, Linux supports standard file systems for disks, ext3, and virtual special file systems.

Device Management:

Almost every system operation in a Linux system is eventually mapped to one or more physical devices. Except for a few hardware resources such as processor and memory, any kind of device control operation is carried out by the device-specific driver code. The kernel must provide a driver for every peripheral that may be operated in the system.

Network Management:

The kernel supports a variety of network standard protocols and network devices. The network management part can be divided into network protocol stack and network device driver. The network protocol stack is responsible for implementing every possible network transport protocol (TCP/IP protocol, etc.); the network device driver is responsible for communicating with various network hardware devices or virtual devices.

At this point, the study of "what are the functions of the Linux kernel" is over. I hope to be able to solve your doubts. The collocation of theory and practice can better help you learn, go and try it! If you want to continue to learn more related knowledge, please continue to follow the website, the editor will continue to work hard to bring you more practical articles!

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