feature-removal-schedule.txt 9.0 KB

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  1. The following is a list of files and features that are going to be
  2. removed in the kernel source tree. Every entry should contain what
  3. exactly is going away, why it is happening, and who is going to be doing
  4. the work. When the feature is removed from the kernel, it should also
  5. be removed from this file.
  6. ---------------------------
  7. What: devfs
  8. When: July 2005
  9. Files: fs/devfs/*, include/linux/devfs_fs*.h and assorted devfs
  10. function calls throughout the kernel tree
  11. Why: It has been unmaintained for a number of years, has unfixable
  12. races, contains a naming policy within the kernel that is
  13. against the LSB, and can be replaced by using udev.
  14. Who: Greg Kroah-Hartman <greg@kroah.com>
  15. ---------------------------
  16. What: RAW driver (CONFIG_RAW_DRIVER)
  17. When: December 2005
  18. Why: declared obsolete since kernel 2.6.3
  19. O_DIRECT can be used instead
  20. Who: Adrian Bunk <bunk@stusta.de>
  21. ---------------------------
  22. What: drivers depending on OBSOLETE_OSS_DRIVER
  23. When: January 2006
  24. Why: OSS drivers with ALSA replacements
  25. Who: Adrian Bunk <bunk@stusta.de>
  26. ---------------------------
  27. What: RCU API moves to EXPORT_SYMBOL_GPL
  28. When: April 2006
  29. Files: include/linux/rcupdate.h, kernel/rcupdate.c
  30. Why: Outside of Linux, the only implementations of anything even
  31. vaguely resembling RCU that I am aware of are in DYNIX/ptx,
  32. VM/XA, Tornado, and K42. I do not expect anyone to port binary
  33. drivers or kernel modules from any of these, since the first two
  34. are owned by IBM and the last two are open-source research OSes.
  35. So these will move to GPL after a grace period to allow
  36. people, who might be using implementations that I am not aware
  37. of, to adjust to this upcoming change.
  38. Who: Paul E. McKenney <paulmck@us.ibm.com>
  39. ---------------------------
  40. What: raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN
  41. When: November 2005
  42. Why: Deprecated in favour of the new ioctl-based rawiso interface, which is
  43. more efficient. You should really be using libraw1394 for raw1394
  44. access anyway.
  45. Who: Jody McIntyre <scjody@steamballoon.com>
  46. ---------------------------
  47. What: Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  48. When: July 2006
  49. Why: V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  50. series. The old API have lots of drawbacks and don't provide enough
  51. means to work with all video and audio standards. The newer API is
  52. already available on the main drivers and should be used instead.
  53. Newer drivers should use v4l_compat_translate_ioctl function to handle
  54. old calls, replacing to newer ones.
  55. Decoder iocts are using internally to allow video drivers to
  56. communicate with video decoders. This should also be improved to allow
  57. V4L2 calls being translated into compatible internal ioctls.
  58. Who: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  59. ---------------------------
  60. What: remove EXPORT_SYMBOL(panic_timeout)
  61. When: April 2006
  62. Files: kernel/panic.c
  63. Why: No modular usage in the kernel.
  64. Who: Adrian Bunk <bunk@stusta.de>
  65. ---------------------------
  66. What: remove EXPORT_SYMBOL(insert_resource)
  67. When: April 2006
  68. Files: kernel/resource.c
  69. Why: No modular usage in the kernel.
  70. Who: Adrian Bunk <bunk@stusta.de>
  71. ---------------------------
  72. What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  73. When: November 2005
  74. Files: drivers/pcmcia/: pcmcia_ioctl.c
  75. Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
  76. normal hotpluggable bus, and with it using the default kernel
  77. infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  78. control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  79. unnecessary, and makes further cleanups and integration of the
  80. PCMCIA subsystem into the Linux kernel device driver model more
  81. difficult. The features provided by cardmgr and cardctl are either
  82. handled by the kernel itself now or are available in the new
  83. pcmciautils package available at
  84. http://kernel.org/pub/linux/utils/kernel/pcmcia/
  85. Who: Dominik Brodowski <linux@brodo.de>
  86. ---------------------------
  87. What: ip_queue and ip6_queue (old ipv4-only and ipv6-only netfilter queue)
  88. When: December 2005
  89. Why: This interface has been obsoleted by the new layer3-independent
  90. "nfnetlink_queue". The Kernel interface is compatible, so the old
  91. ip[6]tables "QUEUE" targets still work and will transparently handle
  92. all packets into nfnetlink queue number 0. Userspace users will have
  93. to link against API-compatible library on top of libnfnetlink_queue
  94. instead of the current 'libipq'.
  95. Who: Harald Welte <laforge@netfilter.org>
  96. ---------------------------
  97. What: remove EXPORT_SYMBOL(kernel_thread)
  98. When: August 2006
  99. Files: arch/*/kernel/*_ksyms.c
  100. Why: kernel_thread is a low-level implementation detail. Drivers should
  101. use the <linux/kthread.h> API instead which shields them from
  102. implementation details and provides a higherlevel interface that
  103. prevents bugs and code duplication
  104. Who: Christoph Hellwig <hch@lst.de>
  105. ---------------------------
  106. What: CONFIG_FORCED_INLINING
  107. When: June 2006
  108. Why: Config option is there to see if gcc is good enough. (in january
  109. 2006). If it is, the behavior should just be the default. If it's not,
  110. the option should just go away entirely.
  111. Who: Arjan van de Ven
  112. ---------------------------
  113. What: START_ARRAY ioctl for md
  114. When: July 2006
  115. Files: drivers/md/md.c
  116. Why: Not reliable by design - can fail when most needed.
  117. Alternatives exist
  118. Who: NeilBrown <neilb@suse.de>
  119. ---------------------------
  120. What: au1x00_uart driver
  121. When: January 2006
  122. Why: The 8250 serial driver now has the ability to deal with the differences
  123. between the standard 8250 family of UARTs and their slightly strange
  124. brother on Alchemy SOCs. The loss of features is not considered an
  125. issue.
  126. Who: Ralf Baechle <ralf@linux-mips.org>
  127. ---------------------------
  128. What: eepro100 network driver
  129. When: January 2007
  130. Why: replaced by the e100 driver
  131. Who: Adrian Bunk <bunk@stusta.de>
  132. ---------------------------
  133. What: pci_module_init(driver)
  134. When: January 2007
  135. Why: Is replaced by pci_register_driver(pci_driver).
  136. Who: Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
  137. ---------------------------
  138. What: Usage of invalid timevals in setitimer
  139. When: March 2007
  140. Why: POSIX requires to validate timevals in the setitimer call. This
  141. was never done by Linux. The invalid (e.g. negative timevals) were
  142. silently converted to more or less random timeouts and intervals.
  143. Until the removal a per boot limited number of warnings is printed
  144. and the timevals are sanitized.
  145. Who: Thomas Gleixner <tglx@linutronix.de>
  146. ---------------------------
  147. What: I2C interface of the it87 driver
  148. When: January 2007
  149. Why: The ISA interface is faster and should be always available. The I2C
  150. probing is also known to cause trouble in at least one case (see
  151. bug #5889.)
  152. Who: Jean Delvare <khali@linux-fr.org>
  153. ---------------------------
  154. What: remove EXPORT_SYMBOL(tasklist_lock)
  155. When: August 2006
  156. Files: kernel/fork.c
  157. Why: tasklist_lock protects the kernel internal task list. Modules have
  158. no business looking at it, and all instances in drivers have been due
  159. to use of too-lowlevel APIs. Having this symbol exported prevents
  160. moving to more scalable locking schemes for the task list.
  161. Who: Christoph Hellwig <hch@lst.de>
  162. ---------------------------
  163. What: mount/umount uevents
  164. When: February 2007
  165. Why: These events are not correct, and do not properly let userspace know
  166. when a file system has been mounted or unmounted. Userspace should
  167. poll the /proc/mounts file instead to detect this properly.
  168. Who: Greg Kroah-Hartman <gregkh@suse.de>
  169. ---------------------------
  170. What: Support for NEC DDB5074 and DDB5476 evaluation boards.
  171. When: June 2006
  172. Why: Board specific code doesn't build anymore since ~2.6.0 and no
  173. users have complained indicating there is no more need for these
  174. boards. This should really be considered a last call.
  175. Who: Ralf Baechle <ralf@linux-mips.org>
  176. ---------------------------
  177. What: USB driver API moves to EXPORT_SYMBOL_GPL
  178. When: Febuary 2008
  179. Files: include/linux/usb.h, drivers/usb/core/driver.c
  180. Why: The USB subsystem has changed a lot over time, and it has been
  181. possible to create userspace USB drivers using usbfs/libusb/gadgetfs
  182. that operate as fast as the USB bus allows. Because of this, the USB
  183. subsystem will not be allowing closed source kernel drivers to
  184. register with it, after this grace period is over. If anyone needs
  185. any help in converting their closed source drivers over to use the
  186. userspace filesystems, please contact the
  187. linux-usb-devel@lists.sourceforge.net mailing list, and the developers
  188. there will be glad to help you out.
  189. Who: Greg Kroah-Hartman <gregkh@suse.de>
  190. ---------------------------
  191. What: find_trylock_page
  192. When: January 2007
  193. Why: The interface no longer has any callers left in the kernel. It
  194. is an odd interface (compared with other find_*_page functions), in
  195. that it does not take a refcount to the page, only the page lock.
  196. It should be replaced with find_get_page or find_lock_page if possible.
  197. This feature removal can be reevaluated if users of the interface
  198. cannot cleanly use something else.
  199. Who: Nick Piggin <npiggin@suse.de>
  200. ---------------------------