Linux 4.9 kernel officially released! To see what's updated? _linux

Objective

After 8 RC versions, the Linux 4.9 version of the kernel on December 11, 2016 as scheduled to meet with you. According to Linux founder Linus Torvalds, the Linux Kernel 4.9 branch will be a major version update, with 8 research and development versions. Linus Torvalds on December 11, 2016 on the kernel mailing list officially released Linux Kernel 4.9, a new mainline (mainline) version, which also marks the opening of the Merge window with version 4.10

1. Linux Introduction

What is the greatest software of the 20th century? I think it must be Linux, without Linux, without today's internet, mobile Internet, IoT, and no more than 87% market share of smartphone operating system Android (data Source: Strategy Analytics Q3 Quarterly data).

1.1 What is Linux

Linux is a clone of the UNIX system, written from scratch by Linus Torvalds and some loosely organized hackers. is a POSIX-compliant Unix-like multiuser, multitasking, multithreaded, and multiple-CPU operating system.

It has all the features and features of the UNIX system you expect, including real multitasking, virtual memory, shared libraries, on-demand loading, shared write-time replication executables, appropriate memory management, and modular networks including IPV4 and IPV6.

Linux is based on the GNU General Public License issue.

1.2 Linux kernel (lernel)

is an integrated kernel system, technically or strictly speaking, the term Linux only represents the Linux kernel of the system. CentOS, Ubuntu, Red Hat, Debian, fedora and other distributions are the basic Linux kernel for further development and distribution. Linux's founders and their team are only responsible for the development and maintenance of the kernel's Linux kernel. Linux kernel source code hosted in GitHub, the URL is as follows: Https://github.com/torvalds/linux

Note: Git is also led by Linus Torvalds, an open source version control software developed to help manage Linux kernel development. PS: Great people create great systems, and at the same time produce a great number of powerful tools to salute. )

1.3 Linux Distribution

We often hear the concept of Linux distributions. Linux distributions are those organized by loosely organized teams, business organizations, or volunteers. Typically includes system software and applications, as well as an installation tool to simplify the initial installation of the system, and software managers that upgrade software installation (such as RPM, DPKG).

such as the CentOS, Ubuntu, Red Hat, Debian, Fedora and other Linux systems mentioned above are a Linux distribution. They are all developed based on the same Linux kernel, but integrate different system software and application software, and system initialization installation tools and software Manager.

Because the same Linux kernel is used for different distributions, the Linux platform has good compatibility and cross-platform portability, allowing the same software to run in different distributions. Therefore, so that Linux has other systems can not match, pet big software ecosystem.

The role and composition of 1.4 Linux kernel (lernel)

Computer system is a symbiotic body of hardware and software, they are interdependent and indivisible. A computer contains integrated devices for processors, memory, hard disks, and other peripherals. But there is no software to operate and control, it can not work itself. The software that completes this control is called the operating system, which is called the kernel (kernel) in Linux.

The composition of the Linux kernel

The Linux kernel consists of the following modules:

1. Processes management (Process Management)
2. Timer (timer)
3. Interrupt Management (Interrupt Management)
4. Memory Management (Memory Management)
5. Modular Management (module Management)
6. Virtual file System interface (VFS Layer)
7. FileSystem (File System)
8. Device driver (Device Driver)
9. Inter-process communication (inter-process communication)
10. Network Management (Network Management)
11. System startup (Iystem Init)
12. Other
    

Linux kernel version number

In the Linux development process, three different version naming schemes have been used:

1, earlier version-the first version is 0.01. Subsequently, 0.02, 0.03, 0.10, 0.11, 0.12 (first GPL version), 0.95, 0.96, 0.97, 0.98, 0.991.0.

2, the old plan, the number consists of three parts of A.B.C (between 1.0 and 2.6)-a represents the major version number, B represents the minor major version number, and c a smaller last version number. In the meantime, a has changed only two times, 1994 years, 1.0 and 1996 of 2.0.

B is used to determine whether Linux is stable, even B is stable, odd-numbered B represents the development version

C indicates the number of bug fixes, security, new features, and drive updates

3, time-based presentation-2.6.0, people think that a shorter release cycle should be used. Indicates that the format update is A.B.C. Where A and b remain unchanged; C represents the kernel version; d indicates bug fixes, security patches, new features, and so on, usually with ' RC '

2. What are the updates to the Linux 4.9 kernel

After the release of Linux Kernel 4.9, 4.9 will be the newest backbone branch (mainline). Linus also says 4.9 is a major update, and the release of the release also marks the opening of the 4.10 Full and window, merging cycle of about two weeks, which will be closed before and after Christmas.

The changes that are brought in the 4.9-card kernel are:

1. Virtual map kernel stack (virtually mapped kernel stacks)
2. Memory Protection Key System call (Memory-protection keys systems calls)
3. BBR Congestion Control algorithm (BBR Congestion-control algorithm)
4. Greybus Bus architecture Support (Support for the Greybus buses architecture)
5. Virtual map kernel stack (virtually mapped kernel stacks)
6. XFS file System share extension (shared extents in the XFS filesystem)
7. Bug Modification and other ...

Summarize

The above is the entire content of this article, I hope the content of this article for everyone's study or work can bring certain help, if you have questions you can message exchange.