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>
diff --git a/init/Kconfig b/init/Kconfig
index 52847ee..d9d3dba 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -423,27 +423,37 @@
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"