Which Linux kernel version is "stable"? | Linux China __linux

Every time Linus Torvalds releases a mainline version of a new Linux kernel, this confusion is almost all about which kernel version is the latest "stable version." It's the new x.y, or the x.y-1 in front. Z. The latest kernel version is not too "new". You should not insist on using the previous version. --Konstantin Ryabitsev
This article navigates ◈ candidate release (RC) 28%◈bug repair 37%◈ The latest stable kernel 51% compiled from | Https://www.linux.com/blog/learn/2018/2/which-linux-kernel-version-stable
Author | Konstantin Ryabitsev
Translator | Qhwdw

Konstantin Ryabitsev explains to you which Linux kernel version can be considered "stable" and how you should choose a kernel version that applies to you.

Every time Linus Torvalds releases the mainline version of a new Linux kernel [1], it almost always causes this confusion, that is, which kernel version is the latest "stable version." It's the new x.y, or the x.y-1 in front. Z. The latest kernel version is not too "new". You should not insist on using the previous version.

KERNEL.ORG[2] The information on the Web page will not help you solve the puzzle. Currently, at the top of the page, we see that the latest stable version of the kernel is 4.15-but below this table, 4.14.16 is also listed as "stable version stable", and 4.15 is listed as "mainline version mainline", very confusing, right.

Unfortunately, this question is not a good answer. The word "stability" we use here has two different meanings: first, as the first name of the Git tree, the second is to say that the kernel can be viewed as "stable" and used in "production systems".

Because of the distributed nature of Git, Linux development works in many different fork warehouses [3]. All bug fixes and new features are first collected and prepared by the individual subsystem maintainers and then submitted to Linus Torvalds, Linus Torvalds included in his own Linux tree [4], and his git tree is considered a "master" of the Git repository ”。 We call this tree the "mainline" Linux tree.

Candidate Release version (RC)

Before each new kernel release, it went through several rounds of "release Candidate," which was tested by the developers and "polished" all of these cool new features. Based on their feedback from these rounds of tests, Linus decides whether the final version is ready. There are usually 7 weekly pre-release versions, but this number often goes to-rc8, and sometimes even-rc9 and above. When Linus was sure that the new kernel was all right, he made the final release, which we call the "stable version", which means it is no longer a "release candidate."

BUG fixes

Like any complex software written by a person who is not perfect, a new version of any Linux kernel contains bugs, and the bugs must be fixed. The bug fix rule for the Linux kernel is simple: All fixes must first go into the Linus tree. Once the bug in the mainline warehouse is fixed, it is then applied to the published kernel that the kernel development community is still maintaining. Before they are considered for fetching to a stable release, all bug fixes must meet a set of important criteria [one of the 5]-standards is that they "must already exist in the Linus tree". This is a standalone Git warehouse [6], which is maintained for fetch bug fixes, and it is also known as the "stable" tree-because it is used to track previously released stable kernels. The tree was planned and maintained by Greg Kroah-hartman.

The latest stable kernel

So, whenever you visit the kernel.org Web site to view the latest stable kernel, you should use the "latest stable kernel" that is described in the big yellow button.

However, you may be surprised to find that both--4.15 and 4.14.16 are stable versions, so which one is more "stable". Some people are reluctant to use the kernel release of ". 0" because they think it is not "stable" enough until the latest is ". 1". It is difficult to prove or refute the right and wrong of this view, both of which have reasons for or against it, so the choice depends on your preference.

On the one hand, any distribution that enters the stable tree must first be accepted into the mainline kernel version and then fetched to the released version. This means that the core version of the kernel always contains the latest bug fixes compared to the distribution in the stable tree, so if you want to use a distribution that contains the fewest known bugs, then the ". 0" Mainline distribution is the best choice.

On the other hand, the mainline version adds all the cool new features-and the new features give them an unknown number of "new bugs" that will not exist in the old stable version. and whether new, unknown bugs are more worrying than old, known bugs that have not been fixed. -It depends on your choice. The point to note, however, is that many bug fixes only thoroughly test the kernel's mainline version. When patches are fetched to the old kernel, they may work well, but they rarely do integration testing with the old kernel. It is generally assumed that the "previous stable version" is close enough to the current mainline version that is sure to be available for production systems. And it's really true, of course, which is why it's very difficult to choose which kernel version is more stable.

So fundamentally, we don't have quantitative or qualitative means to tell you exactly which kernel version is more stable--4.15 or 4.14.16. All we can do is tell you that they have "different stability" (the answer may not help you, but at least you understand what the differences are.) ）。

Learn more about Linux by "Understanding Linux" from the Linux Foundation and EdX free courses [7].

Via:https://www.linux.com/blog/learn/2018/2/which-linux-kernel-version-stable

Author: KONSTANTIN ryabitsev[9] Translator: QHWDW proofreading: Wxy

This article by LCTT original compilation, the Linux China Honor launches LCTT translator QHWDW???? Total Translation: 69 contribution time: 107 days

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