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-.TH SYSFS 5 2017-09-10 "Linux" "Linux Programmer's Manual"
+.TH sysfs 5 (date) "Linux man-pages (unreleased)"
.SH NAME
sysfs \- a filesystem for exporting kernel objects
.SH DESCRIPTION
(More precisely, the files and directories in
.B sysfs
provide a view of the
-.IR kobject
+.I kobject
structures defined internally within the kernel.)
The files under
.B sysfs
.I /sys
hierarchy.
.TP
-.IR /sys/block
+.I /sys/block
This subdirectory contains one symbolic link for each block device
that has been discovered on the system.
The symbolic links point to corresponding directories under
.IR /sys/devices .
.TP
-.IR /sys/bus
+.I /sys/bus
This directory contains one subdirectory for each of the bus types
in the kernel.
Inside each of these directories are two subdirectories:
.RS
.TP
-.IR devices
+.I devices
This subdirectory contains symbolic links to entries in
-.IR /sys/devices
+.I /sys/devices
that correspond to the devices discovered on this bus.
.TP
-.IR drivers
+.I drivers
This subdirectory contains one subdirectory for each device driver
that is loaded on this bus.
.RE
.TP
-.IR /sys/class
+.I /sys/class
This subdirectory contains a single layer of further subdirectories
for each of the device classes that have been registered on the system
(e.g., terminals, network devices, block devices, graphics devices,
Inside each of these subdirectories are symbolic links for each of the
devices in this class.
These symbolic links refer to entries in the
-.IR /sys/devices
+.I /sys/devices
directory.
.TP
-.IR /sys/class/net
+.I /sys/class/net
Each of the entries in this directory is a symbolic link
-representing on of the real or virtual networking devices
+representing one of the real or virtual networking devices
that are visible in the network namespace of the process
that is accessing the directory.
Each of these symbolic links refers to entries in the
-.IR /sys/devices
+.I /sys/devices
directory.
.TP
-.IR /sys/dev
+.I /sys/dev
This directory contains two subdirectories
-.IR block /
+.I block/
and
.IR char/ ,
corresponding, respectively,
.B sysfs
directory for a device.
The symbolic links inside
-.IR /sys/dev
+.I /sys/dev
thus provide an easy way to look up the
.B sysfs
interface using the device IDs returned by a call to
.EX
$ \fBstat \-c "%t %T" /dev/null\fP
1 3
-$ \fBreadlink /sys/dev/char/1\\:3\fP
+$ \fBreadlink /sys/dev/char/1\e:3\fP
\&../../devices/virtual/mem/null
$ \fBls \-Fd /sys/devices/virtual/mem/null\fP
/sys/devices/virtual/mem/null/
.EE
.in
.TP
-.IR /sys/devices
+.I /sys/devices
This is a directory that contains a filesystem representation of
the kernel device tree,
which is a hierarchy of
.I device
structures within the kernel.
.TP
-.IR /sys/firmware
+.I /sys/firmware
This subdirectory contains interfaces for viewing and manipulating
firmware-specific objects and attributes.
.TP
-.IR /sys/fs
+.I /sys/fs
This directory contains subdirectories for some filesystems.
A filesystem will have a subdirectory here only if it chose
to explicitly create the subdirectory.
.TP
-.IR /sys/fs/cgroup
+.I /sys/fs/cgroup
This directory conventionally is used as a mount point for a
.BR tmpfs (5)
filesystem containing mount points for
.BR cgroups (7)
filesystems.
.TP
-.IR /sys/hypervisor
+.I /sys/fs/smackfs
+The directory contains configuration files for the SMACK LSM.
+See the kernel source file
+.IR Documentation/admin\-guide/LSM/Smack.rst .
+.TP
+.I /sys/hypervisor
[To be documented]
.TP
-.IR /sys/kernel
+.I /sys/kernel
This subdirectory contains various files and subdirectories that provide
information about the running kernel.
.TP
-.IR /sys/kernel/debug/tracing
+.I /sys/kernel/cgroup/
+For information about the files in this directory, see
+.BR cgroups (7).
+.TP
+.I /sys/kernel/debug/tracing
Mount point for the
.I tracefs
filesystem used by the kernel's
see the kernel source file
.IR Documentation/trace/ftrace.txt .)
.TP
-.IR /sys/kernel/mm
+.I /sys/kernel/mm
This subdirectory contains various files and subdirectories that provide
information about the kernel's memory management subsystem.
.TP
-.IR /sys/kernel/mm/hugepages
+.I /sys/kernel/mm/hugepages
This subdirectory contains one subdirectory for each of the
huge page sizes that the system supports.
The subdirectory name indicates the huge page size (e.g.,
-.IR hugepages-2048kB ).
-Within each of these subbdirectories is a set of files
+.IR hugepages\-2048kB ).
+Within each of these subdirectories is a set of files
that can be used to view and (in some cases) change settings
associated with that huge page size.
For further information, see the kernel source file
-.IR Documentation/vm/hugetlbpage.txt .
+.IR Documentation/admin\-guide/mm/hugetlbpage.rst .
.TP
-.IR /sys/module
+.I /sys/module
This subdirectory contains one subdirectory
for each module that is loaded into the kernel.
The name of each directory is the name of the module.
[To be documented]
.RE
.TP
-.IR /sys/power
+.I /sys/power
[To be documented]
-.SH VERSIONS
-The
-.B sysfs
-filesystem first appeared in Linux 2.6.0.
-.SH CONFORMING TO
-The
-.B sysfs
-filesystem is Linux-specific.
+.SH STANDARDS
+Linux.
+.SH HISTORY
+Linux 2.6.0.
.SH NOTES
This manual page is incomplete, possibly inaccurate, and is the kind
of thing that needs to be updated very often.
.BR proc (5),
.BR udev (7)
.PP
-P. Mochel. (2005).
+P.\& Mochel. (2005).
.IR "The sysfs filesystem" .
Proceedings of the 2005 Ottawa Linux Symposium.
.\" https://www.kernel.org/pub/linux/kernel/people/mochel/doc/papers/ols-2005/mochel.pdf
The kernel source file
.I Documentation/filesystems/sysfs.txt
and various other files in
-.IR Documentation/ABI
+.I Documentation/ABI
and
-.IR Documentation/*/sysfs.txt
+.I Documentation/*/sysfs.txt
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