Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756885AbZAGJWB (ORCPT ); Wed, 7 Jan 2009 04:22:01 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753176AbZAGJVo (ORCPT ); Wed, 7 Jan 2009 04:21:44 -0500 Received: from aun.it.uu.se ([130.238.12.36]:38018 "EHLO aun.it.uu.se" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753078AbZAGJVl (ORCPT ); Wed, 7 Jan 2009 04:21:41 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18788.29727.163564.90030@harpo.it.uu.se> Date: Wed, 7 Jan 2009 10:21:35 +0100 From: Mikael Pettersson To: Greg Kroah-Hartman Cc: linux-kernel@vger.kernel.org, Kay Sievers Subject: Re: [PATCH 06/60] sysfs: clarify SYSFS_DEPRECATED help text In-Reply-To: <1231279939-32728-6-git-send-email-gregkh@suse.de> References: <20090106221123.GA32689@kroah.com> <1231279939-32728-6-git-send-email-gregkh@suse.de> X-Mailer: VM 7.17 under Emacs 20.7.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3588 Lines: 80 Greg Kroah-Hartman writes: > From: Kay Sievers > > 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 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 :-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. 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 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/