From fce3e804cfad49208fd2ff9db4bcb57481409e1d Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Sat, 1 Nov 2008 14:03:00 +0100 Subject: 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 Signed-off-by: Greg Kroah-Hartman --- init/Kconfig | 44 +++++++++++++++++++++++++++----------------- 1 file changed, 27 insertions(+), 17 deletions(-) (limited to 'init') diff --git a/init/Kconfig b/init/Kconfig index 52847eec7398..d9d3dbabdb18 100644 --- a/init/Kconfig +++ b/init/Kconfig @@ -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 :-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. - - 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. - - If you are using a distro with the most recent userspace - packages, it should be safe to say N here. + This option switches the layout of sysfs to the deprecated + version. + + 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 + ":" 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. + + 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//cpuset file" -- cgit v1.2.3