sysfs: clarify SYSFS_DEPRECATED help text

This should make the help text of SYSFS_DEPRECATED more clear, that this
is _not_ about (what some people think it is) suppressing a few symlinks
and variables, but a different sysfs _layout_ with new features.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Kay Sievers 2008-11-01 14:03:00 +01:00 committed by Greg Kroah-Hartman
parent 1e0b2cf933
commit fce3e804cf

View file

@ -423,27 +423,37 @@ config SYSFS_DEPRECATED
bool
config SYSFS_DEPRECATED_V2
bool "Create deprecated sysfs files"
bool "Create deprecated sysfs layout for older userspace tools"
depends on SYSFS
default y
select SYSFS_DEPRECATED
help
This option creates deprecated symlinks such as the
"device"-link, the <subsystem>:<name>-link, and the
"bus"-link. It may also add deprecated key in the
uevent environment.
None of these features or values should be used today, as
they export driver core implementation details to userspace
or export properties which can't be kept stable across kernel
releases.
This option switches the layout of sysfs to the deprecated
version.
If enabled, this option will also move any device structures
that belong to a class, back into the /sys/class hierarchy, in
order to support older versions of udev and some userspace
programs.
The current sysfs layout features a unified device tree at
/sys/devices/, which is able to express a hierarchy between
class devices. If the deprecated option is set to Y, the
unified device tree is split into a bus device tree at
/sys/devices/ and several individual class device trees at
/sys/class/. The class and bus devices will be connected by
"<subsystem>:<name>" and the "device" links. The "block"
class devices, will not show up in /sys/class/block/. Some
subsystems will suppress the creation of some devices which
depend on the unified device tree.
If you are using a distro with the most recent userspace
packages, it should be safe to say N here.
This option is not a pure compatibility option that can
be safely enabled on newer distributions. It will change the
layout of sysfs to the non-extensible deprecated version,
and disable some features, which can not be exported without
confusing older userspace tools. Since 2007/2008 all major
distributions do not enable this option, and ship no tools which
depend on the deprecated layout or this option.
If you are using a new kernel on an older distribution, or use
older userspace tools, you might need to say Y here. Do not say Y,
if the original kernel, that came with your distribution, has
this option set to N.
config PROC_PID_CPUSET
bool "Include legacy /proc/<pid>/cpuset file"