This is losely based on previous discussions on linux-kernel [1][2][3]. Lets also refer people reading the stable rules to Documentation/development-process/. Also add the number of days it has taken between releases, and provide the average for the last 10 releases: 86.0 days. [1] http://marc.info/?l=linux-kernel&m=122048427801324&w=2 [2] http://marc.info/?l=linux-netdev&m=122048757705315&w=2 [3] http://marc.info/?l=linux-kernel&m=124515657407679&w=2 Signed-off-by: Luis R. Rodriguez <lrodriguez@xxxxxxxxxxx> --- Documentation/development-process/2.Process | 158 +++++++++++++++++++++++++-- Documentation/stable_kernel_rules.txt | 5 + 2 files changed, 153 insertions(+), 10 deletions(-) diff --git a/Documentation/development-process/2.Process b/Documentation/development-process/2.Process index d750321..d4ca05d 100644 --- a/Documentation/development-process/2.Process +++ b/Documentation/development-process/2.Process @@ -7,20 +7,158 @@ 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. +2.0:SUMMARY + +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 +kernel release. + +2.0.1: PATCH QUEUING FOR THE NEXT KERNEL RELEASE + +Linus maintains the development kernel, this means he accepts new +features and drivers for the next kernel release. He however does not +maintain every single line of the kernel. The kernel is broken down by +different subsystems and each subsystem has its own maintainer. In order +to aid the development of Linux maintainers subsystem have trees where +they queue patches for the next kernel release. This is typically done +with a foo-next-2.6.git tree where foo would be an arbitrary subsystem +name. These trees typically are designed to have a clean git history +to make pulling for Linus easier and as clean as possible. + +Subsystem maintainers can typically have their own development git trees +apart from the foo-next-2.6.git trees as a breeding ground and test ground +for bleeding edge patches. Subsystem maintainers are at complete freedom to +maintain these trees however they see fit. Once patches have been proven +stable enough in a development tree they tend to be moved to their +respective foo-next-2.6.git tree. + +Subsystem development trees are *always* open for development and new patches +are always accepted. After a new kernel is released subsystem maintainers +tend to slow down in accepting patches into their development trees though +so that the new development can eventually be rebased easily ontop of the +next kernel rc1 release. + +If your patch is adding a new feature or changing a lot of code and you send +it between a stable kernel release and prior to the rc1 kernel release it will +likely be a while before it is merged into a development tree, so be patient +during this time. + +2.0.1: MERGE WINDOW + +The merge window opens up after the next stable kernel is released and takes +two weeks. The merge window is when maintainers of different subsystems send +pull requests to Linus for code they have been queuing up for the next stable +kernel. These are the foo-next-2.6.git trees. + +After the merge window the kernel is worked on through the rc-series of the +kernel release. The rc-series focus is to address regressions. The merge window +closes upon the first rc-series release, rc1. + +After a subsystem maintainer has sent his pull request to Linus during the merge +window no further new development will be accepted for that foo-next-2.6.git +tree and as such it marks the closure of development for that subsystem for that +kernel cycle. + +2.0.2: MEETING DEADLINES FOR KERNEL RELEASES + +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 so the community can review it +and it can eventually be merged into the appropriate development subsystem tree. + +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. + +A good indication of when the next stable kernel release will be made is when +Linus notes the last rc cycle released may be the last. By this time 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 development 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. + +2.0.3: RC-SERIES RULES + +This section summarizes what kind of patches are accepted after a new stable kernel is +released, before the merge window closes and after it closes. These patches are targeted +for the kernel prior to its final release. + +2.0.3.0: RC-SERIES RULES PRIOR TO THE RC1 RELEASE + +Before the merge window closes, prior to the rc1 release, Linus accepts pull requests +from different subsystem maintainers, with it go all the queued up material for the +next kernel release for each respective subsystem, on all foo-next-2.6.git trees. +After subsystem maintainers have sent their pull requests there are strict rules +for new patches prior to the close of the merge window, marked by the rc1 release: + + - patches must fix a regression + - patches must fix a security hole + - patches must fix a oops/kernel hang + +Non-intrusive bug fixes fixes will very likely not be accepted. Some maintainers +may choose to accept some non-intrusive patches, depending on their work load. +You should however not take it for granted such patches will get accepted. You +should always just target the development kernel and provide a good commit to +help with review. + +When in doubt consult with your subsystem maintainer or just allow him to +do the judging of where the patches deserves to go to, an excellent commit log +should help with this effort. + +2.0.3.1: RC-SERIES RULES AFTER THE RC1 RELEASE + +Linus does not accept more pull requests from subsystem maintainers after the +rc1 release. This means you can expect no new features or new development after +rc1. + +The same type of patches are accepted after the rc1 release with the addition +of a slight warmer welcome for non-intrusive bug fix patches. Non-intrusive +bug fixes must be important and address very clearly the bug they are fixing. +Non-intrusive bug fixes can fix issues which are not a regression, security +hole or a kernel oops/hang. + +Linus will not accept non-intrusive bug fix patches late in the rc-series, after +the rc5, for example. + +You should never take it for granted non-intrusive bug fixes will be accepted. +Ultimately it is up to the subsystem maintainers to decide whether to accept +such a fix or not, which is why your commit log entry is critically important. +You want to provide as much detail as is posisible in order to help maintainers +make the right call. + +2.0.4 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 for it +cannot regress as no previous kernels exists with it. + +After a driver has been present for one kernel release the relaxed rules for +it during the rc-series are no longer applicable. 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 diff --git a/Documentation/stable_kernel_rules.txt b/Documentation/stable_kernel_rules.txt index a452227..113e8c8 100644 --- a/Documentation/stable_kernel_rules.txt +++ b/Documentation/stable_kernel_rules.txt @@ -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: + +Documentation/development-process/ + Rules on what kind of patches are accepted, and which ones are not, into the "-stable" tree: -- 1.6.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
