@@ -7,20 +7,96 @@ course of one year, the kernel has since had to evolve a number of
processes to keep development happening smoothly. A solid understanding of
how the process works is required in order to be an effective part of it.
+This section provides a brief summary of the kernel release rules.
+2.0.0: KERNEL RELEASE RULES
+Stable kernels are released when they are ready! This means there are
+absolutely no strict guidelines for sticking to specific dates for a
+2.0.1: MERGE WINDOW
+The merge window opens up after the next stable kernel is released.
+The merge window is when maintainers of different subsystem send pull
+requests to Linus for code they have been queuing up for the next
+stable kernel. This is typically now done through respective
+foo-next-2.6.git trees where foo is your subsystem. Each maintainer
+queues up patches for the next kernel cycle in this foo-next-2.6.git
+tree. After the merge window the kernel is worked on through the
+rc-series of the kernel release. The merge window closes at the first
+After a maintainer has sent his pull request to Linus during the merge
+window no further new development will be accepted for that tree and
+as such it marks the closure of development for that subsystem for that
+kernel cycle. Developers wishing to target deadlines should simply work
+on their development without regards or consideration for inclusion to
+a specific kernel release. Once development is done it should simply be
+posted. If you insist on targeting a kernel release for deadlines you can
+try to be aware of the current rc cycle development and how soon it seems
+the next stable kernel release will be made. When Linus notes the last rc
+cycle released may be the last -- that is a good sign you should already
+have all your development done and merged in the respective development
+tree. If your code is not ready and merged into the respective maintainers
+tree prior to the announced last potential rc kernel release chances are
+you missed getting your code in for the next kernel merge window.
+Exemptions here are new drivers, covered below.
+2.0.2: RC-SERIES RULES
+Rules on what kind of patches are accepted after the merge window closes.
+These are patches targeted for the kernel rc-series of a kernel prior
+to its release.
+ - it must fix a reported regression
+ - it must fix a reported security hole
+ - it must fix a reported oops/kernel hang
+This means any small-non-fix code changes, although they might fix an issue,
+will not be accepted. If the patch in question is for a driver that has been
+around for more than a kernel release, then "small fixes" really can't be
+worth all that much. And "small fixes" may be small and "obvious" they
+definitely can regress.
+When in doubt consult with your subsystem maintainer or just allow him to
+do the judging of where the patches deserves to go to, a proper commit log
+should help with this effort.
+2.0.3 RC-SERIES NEW DRIVER EXEMPTION RULE
+The very first release a new driver (or filesystem) is special. New drivers
+are accepted during the rc series. Patches for the same driver then are
+also accepted during the same rc series of a kernel as well as fixes as it
+cannot regress as no previous kernels exists with it.
+Once drivers are upstream for one kernel release (say on 2.6.29) the target
+*goal* after the merge window of the next kernel (respectively this would be
+the 2.6.30 rc-series) is to address regressions. Kernel oops/hangs and security
+issues are obviously accepted but the point is these should have also been
+caught earlier as a general development goal. The rc-series focus should really
+be to address regressions.
2.1: THE BIG PICTURE
The kernel developers use a loosely time-based release process, with a new
-major kernel release happening every two or three months. The recent
-release history looks like this:
- 2.6.26 July 13, 2008
- 2.6.25 April 16, 2008
- 2.6.24 January 24, 2008
- 2.6.23 October 9, 2007
- 2.6.22 July 8, 2007
- 2.6.21 April 25, 2007
- 2.6.20 February 4, 2007
+major kernel release happening about every two or three months. The current
+average time based on the last 10 releases is 86.0 days. The recent release
+history along with the number of days between each release looks like this:
+ 2.6.30 June 10, 2009 - 78 days
+ 2.6.29 March 23, 2009 - 89 days
+ 2.6.28 December 29, 2008 - 76 days
+ 2.6.27 October 8, 2008 - 88 days
+ 2.6.26 July 13, 2008 - 88 days
+ 2.6.25 April 16, 2008 - 83 days
+ 2.6.24 January 24, 2008 - 108 days
+ 2.6.23 October 9, 2007 - 94 days
+ 2.6.22 July 8, 2007 - 75 days
+ 2.6.21 April 25, 2007 - 81 days
+ 2.6.20 February 4, 2007 - 68
Every 2.6.x release is a major kernel release with new features, internal
API changes, and more. A typical 2.6 release can contain over 10,000
@@ -1,5 +1,10 @@
Everything you ever wanted to know about Linux 2.6 -stable releases.
+For further details, such as stable kernel release schedules, rc-series
+policies and process of development please refer to:
Rules on what kind of patches are accepted, and which ones are not, into the