Unlike procfs and sysfs, which are implemented to present specific information through the virtual file interface, debugfs is a generic memory filesystem that allows kernel developers to export any arbitrary information that is deemed useful for debugging. Debugfs provides function interfaces used to enumerate virtual files and is generally mounted to the /sys/debug directory. Debugfs is used by tracing mechanisms such as ftrace to present function and interrupt traces.

There are many other special filesystems such as pipefs, mqueue, and sockfs; we shall touch upon a few of them in later chapters.