For years it has been common practice to use “raw” kernel headers (straight from a kernel tarball) in /usr/include, but over the last few years, the kernel developers have taken a strong stance that this should not be done. This gave birth to the Linux-Libc-Headers Project, which was designed to maintain an Application Programming Interface (API) stable version of the Linux headers.
多年来的公共惯例是使用 /usr/include 目录下"原始的"内核头文件(直接来自于内核源码包),但是近年来,内核开发者强烈要求不要这样做,因此诞生了 Linux-Libc-Headers 项目,其目标是维护一个API(应用程序编程接口)版本稳定的 Linux 头文件。