feature-removal-schedule.txt 8.8 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(insert_resource)
  61. When: April 2006
  62. Files: kernel/resource.c
  63. Why: No modular usage in the kernel.
  64. Who: Adrian Bunk <bunk@stusta.de>
  65. ---------------------------
  66. What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  67. When: November 2005
  68. Files: drivers/pcmcia/: pcmcia_ioctl.c
  69. Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
  70. normal hotpluggable bus, and with it using the default kernel
  71. infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  72. control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  73. unnecessary, and makes further cleanups and integration of the
  74. PCMCIA subsystem into the Linux kernel device driver model more
  75. difficult. The features provided by cardmgr and cardctl are either
  76. handled by the kernel itself now or are available in the new
  77. pcmciautils package available at
  78. http://kernel.org/pub/linux/utils/kernel/pcmcia/
  79. Who: Dominik Brodowski <linux@brodo.de>
  80. ---------------------------
  81. What: ip_queue and ip6_queue (old ipv4-only and ipv6-only netfilter queue)
  82. When: December 2005
  83. Why: This interface has been obsoleted by the new layer3-independent
  84. "nfnetlink_queue". The Kernel interface is compatible, so the old
  85. ip[6]tables "QUEUE" targets still work and will transparently handle
  86. all packets into nfnetlink queue number 0. Userspace users will have
  87. to link against API-compatible library on top of libnfnetlink_queue
  88. instead of the current 'libipq'.
  89. Who: Harald Welte <laforge@netfilter.org>
  90. ---------------------------
  91. What: remove EXPORT_SYMBOL(kernel_thread)
  92. When: August 2006
  93. Files: arch/*/kernel/*_ksyms.c
  94. Why: kernel_thread is a low-level implementation detail. Drivers should
  95. use the <linux/kthread.h> API instead which shields them from
  96. implementation details and provides a higherlevel interface that
  97. prevents bugs and code duplication
  98. Who: Christoph Hellwig <hch@lst.de>
  99. ---------------------------
  100. What: CONFIG_FORCED_INLINING
  101. When: June 2006
  102. Why: Config option is there to see if gcc is good enough. (in january
  103. 2006). If it is, the behavior should just be the default. If it's not,
  104. the option should just go away entirely.
  105. Who: Arjan van de Ven
  106. ---------------------------
  107. What: START_ARRAY ioctl for md
  108. When: July 2006
  109. Files: drivers/md/md.c
  110. Why: Not reliable by design - can fail when most needed.
  111. Alternatives exist
  112. Who: NeilBrown <neilb@suse.de>
  113. ---------------------------
  114. What: au1x00_uart driver
  115. When: January 2006
  116. Why: The 8250 serial driver now has the ability to deal with the differences
  117. between the standard 8250 family of UARTs and their slightly strange
  118. brother on Alchemy SOCs. The loss of features is not considered an
  119. issue.
  120. Who: Ralf Baechle <ralf@linux-mips.org>
  121. ---------------------------
  122. What: eepro100 network driver
  123. When: January 2007
  124. Why: replaced by the e100 driver
  125. Who: Adrian Bunk <bunk@stusta.de>
  126. ---------------------------
  127. What: pci_module_init(driver)
  128. When: January 2007
  129. Why: Is replaced by pci_register_driver(pci_driver).
  130. Who: Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
  131. ---------------------------
  132. What: Usage of invalid timevals in setitimer
  133. When: March 2007
  134. Why: POSIX requires to validate timevals in the setitimer call. This
  135. was never done by Linux. The invalid (e.g. negative timevals) were
  136. silently converted to more or less random timeouts and intervals.
  137. Until the removal a per boot limited number of warnings is printed
  138. and the timevals are sanitized.
  139. Who: Thomas Gleixner <tglx@linutronix.de>
  140. ---------------------------
  141. What: I2C interface of the it87 driver
  142. When: January 2007
  143. Why: The ISA interface is faster and should be always available. The I2C
  144. probing is also known to cause trouble in at least one case (see
  145. bug #5889.)
  146. Who: Jean Delvare <khali@linux-fr.org>
  147. ---------------------------
  148. What: remove EXPORT_SYMBOL(tasklist_lock)
  149. When: August 2006
  150. Files: kernel/fork.c
  151. Why: tasklist_lock protects the kernel internal task list. Modules have
  152. no business looking at it, and all instances in drivers have been due
  153. to use of too-lowlevel APIs. Having this symbol exported prevents
  154. moving to more scalable locking schemes for the task list.
  155. Who: Christoph Hellwig <hch@lst.de>
  156. ---------------------------
  157. What: mount/umount uevents
  158. When: February 2007
  159. Why: These events are not correct, and do not properly let userspace know
  160. when a file system has been mounted or unmounted. Userspace should
  161. poll the /proc/mounts file instead to detect this properly.
  162. Who: Greg Kroah-Hartman <gregkh@suse.de>
  163. ---------------------------
  164. What: Support for NEC DDB5074 and DDB5476 evaluation boards.
  165. When: June 2006
  166. Why: Board specific code doesn't build anymore since ~2.6.0 and no
  167. users have complained indicating there is no more need for these
  168. boards. This should really be considered a last call.
  169. Who: Ralf Baechle <ralf@linux-mips.org>
  170. ---------------------------
  171. What: USB driver API moves to EXPORT_SYMBOL_GPL
  172. When: Febuary 2008
  173. Files: include/linux/usb.h, drivers/usb/core/driver.c
  174. Why: The USB subsystem has changed a lot over time, and it has been
  175. possible to create userspace USB drivers using usbfs/libusb/gadgetfs
  176. that operate as fast as the USB bus allows. Because of this, the USB
  177. subsystem will not be allowing closed source kernel drivers to
  178. register with it, after this grace period is over. If anyone needs
  179. any help in converting their closed source drivers over to use the
  180. userspace filesystems, please contact the
  181. linux-usb-devel@lists.sourceforge.net mailing list, and the developers
  182. there will be glad to help you out.
  183. Who: Greg Kroah-Hartman <gregkh@suse.de>
  184. ---------------------------
  185. What: find_trylock_page
  186. When: January 2007
  187. Why: The interface no longer has any callers left in the kernel. It
  188. is an odd interface (compared with other find_*_page functions), in
  189. that it does not take a refcount to the page, only the page lock.
  190. It should be replaced with find_get_page or find_lock_page if possible.
  191. This feature removal can be reevaluated if users of the interface
  192. cannot cleanly use something else.
  193. Who: Nick Piggin <npiggin@suse.de>
  194. ---------------------------