/sys

The sysfs filesystem is the filesystem to export kernel objects (kobject). It is usually mounted on /sys. It contains information about block devices (/sys/block) and other kernel stuff (Compare with /sys/kernel/debug.

Every registered kobject creates a directory in or under /sys.

A rule mandates that every file in the sysfs must have one value only. /sys/kernel/debug does not belong to the sysfs and therefore, this rule does not apply there).

The sysfs needs the CONFIG_SYSFS configuration option.

Subdirectories

Find subdirectories from in the top level Linux kernel directory with

grep -hrPo '(?<!/proc)/sys/[0-9a-zA-Z_\-]+/' 2>/dev/null | sort -u

`accessibility`
`block`	All block devices
`bus`	contains a flat directory layout of the bus types (PCI, IDE, USB) in the kernel.
`class`	Driver classes (net, sound, usb …)
`crypto`
`debug`
`dev`
`devices`	contains representation of the device tree.
`event_source`
`firmware`
`fs`	contains subdirectories for mounted(?) filesystems.
`hypervisor`
`kernel`
`module`	Currently loaded modules
`modules`	`module` ?
`net`
`o2cb`
`platform`
`power`	Information related to the power management subsystem
`subsystem`

/sys

Subdirectories

See also