557 lines
20 KiB
Plaintext
557 lines
20 KiB
Plaintext
The following is a list of files and features that are going to be
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removed in the kernel source tree. Every entry should contain what
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exactly is going away, why it is happening, and who is going to be doing
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the work. When the feature is removed from the kernel, it should also
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be removed from this file.
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---------------------------
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What: PRISM54
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When: 2.6.34
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Why: prism54 FullMAC PCI / Cardbus devices used to be supported only by the
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prism54 wireless driver. After Intersil stopped selling these
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devices in preference for the newer more flexible SoftMAC devices
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a SoftMAC device driver was required and prism54 did not support
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them. The p54pci driver now exists and has been present in the kernel for
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a while. This driver supports both SoftMAC devices and FullMAC devices.
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The main difference between these devices was the amount of memory which
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could be used for the firmware. The SoftMAC devices support a smaller
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amount of memory. Because of this the SoftMAC firmware fits into FullMAC
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devices's memory. p54pci supports not only PCI / Cardbus but also USB
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and SPI. Since p54pci supports all devices prism54 supports
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you will have a conflict. I'm not quite sure how distributions are
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handling this conflict right now. prism54 was kept around due to
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claims users may experience issues when using the SoftMAC driver.
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Time has passed users have not reported issues. If you use prism54
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and for whatever reason you cannot use p54pci please let us know!
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E-mail us at: linux-wireless@vger.kernel.org
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For more information see the p54 wiki page:
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http://wireless.kernel.org/en/users/Drivers/p54
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Who: Luis R. Rodriguez <lrodriguez@atheros.com>
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---------------------------
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What: IRQF_SAMPLE_RANDOM
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Check: IRQF_SAMPLE_RANDOM
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When: July 2009
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Why: Many of IRQF_SAMPLE_RANDOM users are technically bogus as entropy
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sources in the kernel's current entropy model. To resolve this, every
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input point to the kernel's entropy pool needs to better document the
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type of entropy source it actually is. This will be replaced with
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additional add_*_randomness functions in drivers/char/random.c
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Who: Robin Getz <rgetz@blackfin.uclinux.org> & Matt Mackall <mpm@selenic.com>
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---------------------------
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What: Deprecated snapshot ioctls
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When: 2.6.36
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Why: The ioctls in kernel/power/user.c were marked as deprecated long time
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ago. Now they notify users about that so that they need to replace
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their userspace. After some more time, remove them completely.
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Who: Jiri Slaby <jirislaby@gmail.com>
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---------------------------
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What: The ieee80211_regdom module parameter
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When: March 2010 / desktop catchup
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Why: This was inherited by the CONFIG_WIRELESS_OLD_REGULATORY code,
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and currently serves as an option for users to define an
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ISO / IEC 3166 alpha2 code for the country they are currently
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present in. Although there are userspace API replacements for this
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through nl80211 distributions haven't yet caught up with implementing
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decent alternatives through standard GUIs. Although available as an
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option through iw or wpa_supplicant its just a matter of time before
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distributions pick up good GUI options for this. The ideal solution
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would actually consist of intelligent designs which would do this for
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the user automatically even when travelling through different countries.
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Until then we leave this module parameter as a compromise.
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When userspace improves with reasonable widely-available alternatives for
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this we will no longer need this module parameter. This entry hopes that
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by the super-futuristically looking date of "March 2010" we will have
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such replacements widely available.
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Who: Luis R. Rodriguez <lrodriguez@atheros.com>
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---------------------------
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What: dev->power.power_state
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When: July 2007
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Why: Broken design for runtime control over driver power states, confusing
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driver-internal runtime power management with: mechanisms to support
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system-wide sleep state transitions; event codes that distinguish
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different phases of swsusp "sleep" transitions; and userspace policy
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inputs. This framework was never widely used, and most attempts to
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use it were broken. Drivers should instead be exposing domain-specific
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interfaces either to kernel or to userspace.
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Who: Pavel Machek <pavel@ucw.cz>
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---------------------------
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What: Video4Linux API 1 ioctls and from Video devices.
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When: kernel 2.6.38
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Files: include/linux/videodev.h
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Check: include/linux/videodev.h
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Why: V4L1 AP1 was replaced by V4L2 API during migration from 2.4 to 2.6
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series. The old API have lots of drawbacks and don't provide enough
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means to work with all video and audio standards. The newer API is
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already available on the main drivers and should be used instead.
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Newer drivers should use v4l_compat_translate_ioctl function to handle
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old calls, replacing to newer ones.
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Decoder iocts are using internally to allow video drivers to
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communicate with video decoders. This should also be improved to allow
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V4L2 calls being translated into compatible internal ioctls.
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Compatibility ioctls will be provided, for a while, via
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v4l1-compat module.
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Who: Mauro Carvalho Chehab <mchehab@infradead.org>
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---------------------------
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What: Video4Linux obsolete drivers using V4L1 API
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When: kernel 2.6.38
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Files: drivers/staging/cpia/* drivers/staging/stradis/*
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Check: drivers/staging/cpia/cpia.c drivers/staging/stradis/stradis.c
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Why: There are some drivers still using V4L1 API, despite all efforts we've done
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to migrate. Those drivers are for obsolete hardware that the old maintainer
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didn't care (or not have the hardware anymore), and that no other developer
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could find any hardware to buy. They probably have no practical usage today,
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and people with such old hardware could probably keep using an older version
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of the kernel. Those drivers will be moved to staging on 2.6.37 and, if nobody
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care enough to port and test them with V4L2 API, they'll be removed on 2.6.38.
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Who: Mauro Carvalho Chehab <mchehab@infradead.org>
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---------------------------
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What: sys_sysctl
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When: September 2010
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Option: CONFIG_SYSCTL_SYSCALL
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Why: The same information is available in a more convenient from
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/proc/sys, and none of the sysctl variables appear to be
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important performance wise.
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Binary sysctls are a long standing source of subtle kernel
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bugs and security issues.
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When I looked several months ago all I could find after
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searching several distributions were 5 user space programs and
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glibc (which falls back to /proc/sys) using this syscall.
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The man page for sysctl(2) documents it as unusable for user
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space programs.
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sysctl(2) is not generally ABI compatible to a 32bit user
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space application on a 64bit and a 32bit kernel.
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For the last several months the policy has been no new binary
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sysctls and no one has put forward an argument to use them.
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Binary sysctls issues seem to keep happening appearing so
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properly deprecating them (with a warning to user space) and a
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2 year grace warning period will mean eventually we can kill
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them and end the pain.
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In the mean time individual binary sysctls can be dealt with
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in a piecewise fashion.
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Who: Eric Biederman <ebiederm@xmission.com>
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---------------------------
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What: /proc/<pid>/oom_adj
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When: August 2012
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Why: /proc/<pid>/oom_adj allows userspace to influence the oom killer's
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badness heuristic used to determine which task to kill when the kernel
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is out of memory.
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The badness heuristic has since been rewritten since the introduction of
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this tunable such that its meaning is deprecated. The value was
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implemented as a bitshift on a score generated by the badness()
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function that did not have any precise units of measure. With the
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rewrite, the score is given as a proportion of available memory to the
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task allocating pages, so using a bitshift which grows the score
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exponentially is, thus, impossible to tune with fine granularity.
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A much more powerful interface, /proc/<pid>/oom_score_adj, was
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introduced with the oom killer rewrite that allows users to increase or
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decrease the badness() score linearly. This interface will replace
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/proc/<pid>/oom_adj.
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A warning will be emitted to the kernel log if an application uses this
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deprecated interface. After it is printed once, future warnings will be
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suppressed until the kernel is rebooted.
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---------------------------
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What: remove EXPORT_SYMBOL(kernel_thread)
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When: August 2006
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Files: arch/*/kernel/*_ksyms.c
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Check: kernel_thread
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Why: kernel_thread is a low-level implementation detail. Drivers should
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use the <linux/kthread.h> API instead which shields them from
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implementation details and provides a higherlevel interface that
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prevents bugs and code duplication
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Who: Christoph Hellwig <hch@lst.de>
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---------------------------
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What: Unused EXPORT_SYMBOL/EXPORT_SYMBOL_GPL exports
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(temporary transition config option provided until then)
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The transition config option will also be removed at the same time.
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When: before 2.6.19
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Why: Unused symbols are both increasing the size of the kernel binary
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and are often a sign of "wrong API"
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Who: Arjan van de Ven <arjan@linux.intel.com>
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---------------------------
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What: PHYSDEVPATH, PHYSDEVBUS, PHYSDEVDRIVER in the uevent environment
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When: October 2008
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Why: The stacking of class devices makes these values misleading and
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inconsistent.
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Class devices should not carry any of these properties, and bus
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devices have SUBSYTEM and DRIVER as a replacement.
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Who: Kay Sievers <kay.sievers@suse.de>
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---------------------------
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What: ACPI procfs interface
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When: July 2008
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Why: ACPI sysfs conversion should be finished by January 2008.
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ACPI procfs interface will be removed in July 2008 so that
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there is enough time for the user space to catch up.
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Who: Zhang Rui <rui.zhang@intel.com>
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---------------------------
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What: /proc/acpi/button
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When: August 2007
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Why: /proc/acpi/button has been replaced by events to the input layer
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since 2.6.20.
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Who: Len Brown <len.brown@intel.com>
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---------------------------
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What: /proc/acpi/event
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When: February 2008
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Why: /proc/acpi/event has been replaced by events via the input layer
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and netlink since 2.6.23.
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Who: Len Brown <len.brown@intel.com>
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---------------------------
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What: i386/x86_64 bzImage symlinks
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When: April 2010
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Why: The i386/x86_64 merge provides a symlink to the old bzImage
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location so not yet updated user space tools, e.g. package
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scripts, do not break.
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Who: Thomas Gleixner <tglx@linutronix.de>
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---------------------------
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What: GPIO autorequest on gpio_direction_{input,output}() in gpiolib
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When: February 2010
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Why: All callers should use explicit gpio_request()/gpio_free().
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The autorequest mechanism in gpiolib was provided mostly as a
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migration aid for legacy GPIO interfaces (for SOC based GPIOs).
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Those users have now largely migrated. Platforms implementing
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the GPIO interfaces without using gpiolib will see no changes.
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Who: David Brownell <dbrownell@users.sourceforge.net>
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---------------------------
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What: b43 support for firmware revision < 410
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When: The schedule was July 2008, but it was decided that we are going to keep the
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code as long as there are no major maintanance headaches.
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So it _could_ be removed _any_ time now, if it conflicts with something new.
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Why: The support code for the old firmware hurts code readability/maintainability
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and slightly hurts runtime performance. Bugfixes for the old firmware
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are not provided by Broadcom anymore.
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Who: Michael Buesch <mb@bu3sch.de>
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---------------------------
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What: /sys/o2cb symlink
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When: January 2010
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Why: /sys/fs/o2cb is the proper location for this information - /sys/o2cb
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exists as a symlink for backwards compatibility for old versions of
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ocfs2-tools. 2 years should be sufficient time to phase in new versions
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which know to look in /sys/fs/o2cb.
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Who: ocfs2-devel@oss.oracle.com
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---------------------------
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What: Ability for non root users to shm_get hugetlb pages based on mlock
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resource limits
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When: 2.6.31
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Why: Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or
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have CAP_IPC_LOCK to be able to allocate shm segments backed by
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huge pages. The mlock based rlimit check to allow shm hugetlb is
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inconsistent with mmap based allocations. Hence it is being
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deprecated.
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Who: Ravikiran Thirumalai <kiran@scalex86.org>
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---------------------------
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What: CONFIG_THERMAL_HWMON
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When: January 2009
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Why: This option was introduced just to allow older lm-sensors userspace
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to keep working over the upgrade to 2.6.26. At the scheduled time of
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removal fixed lm-sensors (2.x or 3.x) should be readily available.
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Who: Rene Herman <rene.herman@gmail.com>
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---------------------------
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What: Code that is now under CONFIG_WIRELESS_EXT_SYSFS
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(in net/core/net-sysfs.c)
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When: After the only user (hal) has seen a release with the patches
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for enough time, probably some time in 2010.
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Why: Over 1K .text/.data size reduction, data is available in other
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ways (ioctls)
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Who: Johannes Berg <johannes@sipsolutions.net>
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---------------------------
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What: sysfs ui for changing p4-clockmod parameters
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When: September 2009
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Why: See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and
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e088e4c9cdb618675874becb91b2fd581ee707e6.
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Removal is subject to fixing any remaining bugs in ACPI which may
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cause the thermal throttling not to happen at the right time.
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Who: Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com>
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-----------------------------
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What: __do_IRQ all in one fits nothing interrupt handler
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When: 2.6.32
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Why: __do_IRQ was kept for easy migration to the type flow handlers.
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More than two years of migration time is enough.
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Who: Thomas Gleixner <tglx@linutronix.de>
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-----------------------------
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What: fakephp and associated sysfs files in /sys/bus/pci/slots/
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When: 2011
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Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to
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represent a machine's physical PCI slots. The change in semantics
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had userspace implications, as the hotplug core no longer allowed
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drivers to create multiple sysfs files per physical slot (required
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for multi-function devices, e.g.). fakephp was seen as a developer's
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tool only, and its interface changed. Too late, we learned that
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there were some users of the fakephp interface.
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In 2.6.30, the original fakephp interface was restored. At the same
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time, the PCI core gained the ability that fakephp provided, namely
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function-level hot-remove and hot-add.
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Since the PCI core now provides the same functionality, exposed in:
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/sys/bus/pci/rescan
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/sys/bus/pci/devices/.../remove
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/sys/bus/pci/devices/.../rescan
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there is no functional reason to maintain fakephp as well.
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We will keep the existing module so that 'modprobe fakephp' will
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present the old /sys/bus/pci/slots/... interface for compatibility,
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but users are urged to migrate their applications to the API above.
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After a reasonable transition period, we will remove the legacy
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fakephp interface.
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Who: Alex Chiang <achiang@hp.com>
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---------------------------
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What: CONFIG_RFKILL_INPUT
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When: 2.6.33
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Why: Should be implemented in userspace, policy daemon.
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Who: Johannes Berg <johannes@sipsolutions.net>
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----------------------------
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What: sound-slot/service-* module aliases and related clutters in
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sound/sound_core.c
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When: August 2010
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Why: OSS sound_core grabs all legacy minors (0-255) of SOUND_MAJOR
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(14) and requests modules using custom sound-slot/service-*
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module aliases. The only benefit of doing this is allowing
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use of custom module aliases which might as well be considered
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a bug at this point. This preemptive claiming prevents
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alternative OSS implementations.
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Till the feature is removed, the kernel will be requesting
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both sound-slot/service-* and the standard char-major-* module
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aliases and allow turning off the pre-claiming selectively via
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CONFIG_SOUND_OSS_CORE_PRECLAIM and soundcore.preclaim_oss
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kernel parameter.
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After the transition phase is complete, both the custom module
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aliases and switches to disable it will go away. This removal
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will also allow making ALSA OSS emulation independent of
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sound_core. The dependency will be broken then too.
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Who: Tejun Heo <tj@kernel.org>
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----------------------------
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What: Support for lcd_switch and display_get in asus-laptop driver
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When: March 2010
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Why: These two features use non-standard interfaces. There are the
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only features that really need multiple path to guess what's
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the right method name on a specific laptop.
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Removing them will allow to remove a lot of code an significantly
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clean the drivers.
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This will affect the backlight code which won't be able to know
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if the backlight is on or off. The platform display file will also be
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write only (like the one in eeepc-laptop).
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This should'nt affect a lot of user because they usually know
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when their display is on or off.
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Who: Corentin Chary <corentin.chary@gmail.com>
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----------------------------
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What: sysfs-class-rfkill state file
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When: Feb 2014
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Files: net/rfkill/core.c
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Why: Documented as obsolete since Feb 2010. This file is limited to 3
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states while the rfkill drivers can have 4 states.
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Who: anybody or Florian Mickler <florian@mickler.org>
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----------------------------
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What: sysfs-class-rfkill claim file
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When: Feb 2012
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Files: net/rfkill/core.c
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Why: It is not possible to claim an rfkill driver since 2007. This is
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Documented as obsolete since Feb 2010.
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Who: anybody or Florian Mickler <florian@mickler.org>
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----------------------------
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What: capifs
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When: February 2011
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Files: drivers/isdn/capi/capifs.*
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Why: udev fully replaces this special file system that only contains CAPI
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NCCI TTY device nodes. User space (pppdcapiplugin) works without
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noticing the difference.
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Who: Jan Kiszka <jan.kiszka@web.de>
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----------------------------
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What: KVM paravirt mmu host support
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When: January 2011
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Why: The paravirt mmu host support is slower than non-paravirt mmu, both
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on newer and older hardware. It is already not exposed to the guest,
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and kept only for live migration purposes.
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Who: Avi Kivity <avi@redhat.com>
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----------------------------
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What: iwlwifi 50XX module parameters
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When: 2.6.40
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Why: The "..50" modules parameters were used to configure 5000 series and
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up devices; different set of module parameters also available for 4965
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with same functionalities. Consolidate both set into single place
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in drivers/net/wireless/iwlwifi/iwl-agn.c
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Who: Wey-Yi Guy <wey-yi.w.guy@intel.com>
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----------------------------
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What: iwl4965 alias support
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When: 2.6.40
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Why: Internal alias support has been present in module-init-tools for some
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time, the MODULE_ALIAS("iwl4965") boilerplate aliases can be removed
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with no impact.
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Who: Wey-Yi Guy <wey-yi.w.guy@intel.com>
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---------------------------
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What: xt_NOTRACK
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Files: net/netfilter/xt_NOTRACK.c
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When: April 2011
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Why: Superseded by xt_CT
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Who: Netfilter developer team <netfilter-devel@vger.kernel.org>
|
|
|
|
----------------------------
|
|
|
|
What: IRQF_DISABLED
|
|
When: 2.6.36
|
|
Why: The flag is a NOOP as we run interrupt handlers with interrupts disabled
|
|
Who: Thomas Gleixner <tglx@linutronix.de>
|
|
|
|
----------------------------
|
|
|
|
What: The acpi_sleep=s4_nonvs command line option
|
|
When: 2.6.37
|
|
Files: arch/x86/kernel/acpi/sleep.c
|
|
Why: superseded by acpi_sleep=nonvs
|
|
Who: Rafael J. Wysocki <rjw@sisk.pl>
|
|
|
|
----------------------------
|
|
|
|
What: PCI DMA unmap state API
|
|
When: August 2012
|
|
Why: PCI DMA unmap state API (include/linux/pci-dma.h) was replaced
|
|
with DMA unmap state API (DMA unmap state API can be used for
|
|
any bus).
|
|
Who: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
|
|
|
|
----------------------------
|
|
|
|
What: DMA_xxBIT_MASK macros
|
|
When: Jun 2011
|
|
Why: DMA_xxBIT_MASK macros were replaced with DMA_BIT_MASK() macros.
|
|
Who: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
|
|
|
|
----------------------------
|
|
|
|
What: namespace cgroup (ns_cgroup)
|
|
When: 2.6.38
|
|
Why: The ns_cgroup leads to some problems:
|
|
* cgroup creation is out-of-control
|
|
* cgroup name can conflict when pids are looping
|
|
* it is not possible to have a single process handling
|
|
a lot of namespaces without falling in a exponential creation time
|
|
* we may want to create a namespace without creating a cgroup
|
|
|
|
The ns_cgroup is replaced by a compatibility flag 'clone_children',
|
|
where a newly created cgroup will copy the parent cgroup values.
|
|
The userspace has to manually create a cgroup and add a task to
|
|
the 'tasks' file.
|
|
Who: Daniel Lezcano <daniel.lezcano@free.fr>
|
|
|
|
----------------------------
|
|
|
|
What: iwlwifi disable_hw_scan module parameters
|
|
When: 2.6.40
|
|
Why: Hareware scan is the prefer method for iwlwifi devices for
|
|
scanning operation. Remove software scan support for all the
|
|
iwlwifi devices.
|
|
|
|
Who: Wey-Yi Guy <wey-yi.w.guy@intel.com>
|
|
|
|
----------------------------
|
|
|
|
What: access to nfsd auth cache through sys_nfsservctl or '.' files
|
|
in the 'nfsd' filesystem.
|
|
When: 2.6.40
|
|
Why: This is a legacy interface which have been replaced by a more
|
|
dynamic cache. Continuing to maintain this interface is an
|
|
unnecessary burden.
|
|
Who: NeilBrown <neilb@suse.de>
|
|
|
|
----------------------------
|