feature-removal-schedule.txt 8.9 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 that were depending on OBSOLETE_OSS_DRIVER
  23. (config options already removed)
  24. When: before 2.6.19
  25. Why: OSS drivers with ALSA replacements
  26. Who: Adrian Bunk <bunk@stusta.de>
  27. ---------------------------
  28. What: RCU API moves to EXPORT_SYMBOL_GPL
  29. When: April 2006
  30. Files: include/linux/rcupdate.h, kernel/rcupdate.c
  31. Why: Outside of Linux, the only implementations of anything even
  32. vaguely resembling RCU that I am aware of are in DYNIX/ptx,
  33. VM/XA, Tornado, and K42. I do not expect anyone to port binary
  34. drivers or kernel modules from any of these, since the first two
  35. are owned by IBM and the last two are open-source research OSes.
  36. So these will move to GPL after a grace period to allow
  37. people, who might be using implementations that I am not aware
  38. of, to adjust to this upcoming change.
  39. Who: Paul E. McKenney <paulmck@us.ibm.com>
  40. ---------------------------
  41. What: raw1394: requests of type RAW1394_REQ_ISO_SEND, RAW1394_REQ_ISO_LISTEN
  42. When: November 2005
  43. Why: Deprecated in favour of the new ioctl-based rawiso interface, which is
  44. more efficient. You should really be using libraw1394 for raw1394
  45. access anyway.
  46. Who: Jody McIntyre <scjody@steamballoon.com>
  47. ---------------------------
  48. What: Video4Linux API 1 ioctls and video_decoder.h from Video devices.
  49. When: July 2006
  50. Why: V4L1 AP1 was replaced by V4L2 API. during migration from 2.4 to 2.6
  51. series. The old API have lots of drawbacks and don't provide enough
  52. means to work with all video and audio standards. The newer API is
  53. already available on the main drivers and should be used instead.
  54. Newer drivers should use v4l_compat_translate_ioctl function to handle
  55. old calls, replacing to newer ones.
  56. Decoder iocts are using internally to allow video drivers to
  57. communicate with video decoders. This should also be improved to allow
  58. V4L2 calls being translated into compatible internal ioctls.
  59. Who: Mauro Carvalho Chehab <mchehab@brturbo.com.br>
  60. ---------------------------
  61. What: remove EXPORT_SYMBOL(insert_resource)
  62. When: April 2006
  63. Files: kernel/resource.c
  64. Why: No modular usage in the kernel.
  65. Who: Adrian Bunk <bunk@stusta.de>
  66. ---------------------------
  67. What: PCMCIA control ioctl (needed for pcmcia-cs [cardmgr, cardctl])
  68. When: November 2005
  69. Files: drivers/pcmcia/: pcmcia_ioctl.c
  70. Why: With the 16-bit PCMCIA subsystem now behaving (almost) like a
  71. normal hotpluggable bus, and with it using the default kernel
  72. infrastructure (hotplug, driver core, sysfs) keeping the PCMCIA
  73. control ioctl needed by cardmgr and cardctl from pcmcia-cs is
  74. unnecessary, and makes further cleanups and integration of the
  75. PCMCIA subsystem into the Linux kernel device driver model more
  76. difficult. The features provided by cardmgr and cardctl are either
  77. handled by the kernel itself now or are available in the new
  78. pcmciautils package available at
  79. http://kernel.org/pub/linux/utils/kernel/pcmcia/
  80. Who: Dominik Brodowski <linux@brodo.de>
  81. ---------------------------
  82. What: ip_queue and ip6_queue (old ipv4-only and ipv6-only netfilter queue)
  83. When: December 2005
  84. Why: This interface has been obsoleted by the new layer3-independent
  85. "nfnetlink_queue". The Kernel interface is compatible, so the old
  86. ip[6]tables "QUEUE" targets still work and will transparently handle
  87. all packets into nfnetlink queue number 0. Userspace users will have
  88. to link against API-compatible library on top of libnfnetlink_queue
  89. instead of the current 'libipq'.
  90. Who: Harald Welte <laforge@netfilter.org>
  91. ---------------------------
  92. What: remove EXPORT_SYMBOL(kernel_thread)
  93. When: August 2006
  94. Files: arch/*/kernel/*_ksyms.c
  95. Why: kernel_thread is a low-level implementation detail. Drivers should
  96. use the <linux/kthread.h> API instead which shields them from
  97. implementation details and provides a higherlevel interface that
  98. prevents bugs and code duplication
  99. Who: Christoph Hellwig <hch@lst.de>
  100. ---------------------------
  101. What: CONFIG_FORCED_INLINING
  102. When: June 2006
  103. Why: Config option is there to see if gcc is good enough. (in january
  104. 2006). If it is, the behavior should just be the default. If it's not,
  105. the option should just go away entirely.
  106. Who: Arjan van de Ven
  107. ---------------------------
  108. What: START_ARRAY ioctl for md
  109. When: July 2006
  110. Files: drivers/md/md.c
  111. Why: Not reliable by design - can fail when most needed.
  112. Alternatives exist
  113. Who: NeilBrown <neilb@suse.de>
  114. ---------------------------
  115. What: au1x00_uart driver
  116. When: January 2006
  117. Why: The 8250 serial driver now has the ability to deal with the differences
  118. between the standard 8250 family of UARTs and their slightly strange
  119. brother on Alchemy SOCs. The loss of features is not considered an
  120. issue.
  121. Who: Ralf Baechle <ralf@linux-mips.org>
  122. ---------------------------
  123. What: eepro100 network driver
  124. When: January 2007
  125. Why: replaced by the e100 driver
  126. Who: Adrian Bunk <bunk@stusta.de>
  127. ---------------------------
  128. What: pci_module_init(driver)
  129. When: January 2007
  130. Why: Is replaced by pci_register_driver(pci_driver).
  131. Who: Richard Knutsson <ricknu-0@student.ltu.se> and Greg Kroah-Hartman <gregkh@suse.de>
  132. ---------------------------
  133. What: Usage of invalid timevals in setitimer
  134. When: March 2007
  135. Why: POSIX requires to validate timevals in the setitimer call. This
  136. was never done by Linux. The invalid (e.g. negative timevals) were
  137. silently converted to more or less random timeouts and intervals.
  138. Until the removal a per boot limited number of warnings is printed
  139. and the timevals are sanitized.
  140. Who: Thomas Gleixner <tglx@linutronix.de>
  141. ---------------------------
  142. What: I2C interface of the it87 driver
  143. When: January 2007
  144. Why: The ISA interface is faster and should be always available. The I2C
  145. probing is also known to cause trouble in at least one case (see
  146. bug #5889.)
  147. Who: Jean Delvare <khali@linux-fr.org>
  148. ---------------------------
  149. What: remove EXPORT_SYMBOL(tasklist_lock)
  150. When: August 2006
  151. Files: kernel/fork.c
  152. Why: tasklist_lock protects the kernel internal task list. Modules have
  153. no business looking at it, and all instances in drivers have been due
  154. to use of too-lowlevel APIs. Having this symbol exported prevents
  155. moving to more scalable locking schemes for the task list.
  156. Who: Christoph Hellwig <hch@lst.de>
  157. ---------------------------
  158. What: mount/umount uevents
  159. When: February 2007
  160. Why: These events are not correct, and do not properly let userspace know
  161. when a file system has been mounted or unmounted. Userspace should
  162. poll the /proc/mounts file instead to detect this properly.
  163. Who: Greg Kroah-Hartman <gregkh@suse.de>
  164. ---------------------------
  165. What: Support for NEC DDB5074 and DDB5476 evaluation boards.
  166. When: June 2006
  167. Why: Board specific code doesn't build anymore since ~2.6.0 and no
  168. users have complained indicating there is no more need for these
  169. boards. This should really be considered a last call.
  170. Who: Ralf Baechle <ralf@linux-mips.org>
  171. ---------------------------
  172. What: USB driver API moves to EXPORT_SYMBOL_GPL
  173. When: Febuary 2008
  174. Files: include/linux/usb.h, drivers/usb/core/driver.c
  175. Why: The USB subsystem has changed a lot over time, and it has been
  176. possible to create userspace USB drivers using usbfs/libusb/gadgetfs
  177. that operate as fast as the USB bus allows. Because of this, the USB
  178. subsystem will not be allowing closed source kernel drivers to
  179. register with it, after this grace period is over. If anyone needs
  180. any help in converting their closed source drivers over to use the
  181. userspace filesystems, please contact the
  182. linux-usb-devel@lists.sourceforge.net mailing list, and the developers
  183. there will be glad to help you out.
  184. Who: Greg Kroah-Hartman <gregkh@suse.de>
  185. ---------------------------
  186. What: find_trylock_page
  187. When: January 2007
  188. Why: The interface no longer has any callers left in the kernel. It
  189. is an odd interface (compared with other find_*_page functions), in
  190. that it does not take a refcount to the page, only the page lock.
  191. It should be replaced with find_get_page or find_lock_page if possible.
  192. This feature removal can be reevaluated if users of the interface
  193. cannot cleanly use something else.
  194. Who: Nick Piggin <npiggin@suse.de>
  195. ---------------------------