> For the complete documentation index, see [llms.txt](https://tinylab-1.gitbook.io/linux-doc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://tinylab-1.gitbook.io/linux-doc/documentation.md).

# Introduction

From [Linux 3.18.y Documentation/](https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/tree/Documentation?id=refs/tags/v3.18.20)