Messages in this thread | | | Date | Wed, 7 Jan 2009 10:21:35 +0100 | From | Mikael Pettersson <> | Subject | Re: [PATCH 06/60] sysfs: clarify SYSFS_DEPRECATED help text |
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Greg Kroah-Hartman writes: > From: Kay Sievers <kay.sievers@vrfy.org> > > 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> > --- > init/Kconfig | 44 +++++++++++++++++++++++++++----------------- > 1 files changed, 27 insertions(+), 17 deletions(-) > > diff --git a/init/Kconfig b/init/Kconfig > index 52847ee..d9d3dba 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 <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. > - > - 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 > + "<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. > + > + 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.
Instead of making vague references to "older" tools, could someone please make a list of the major tools that depend on sysfs, and the minimal/oldest versions needed for the non-deprecated layout?
/Mikael
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