We appear to have a gap in our process docs. We go into detail on how to contribute code to the kernel, and how to be a subsystem maintainer. I can't find any docs directed towards the thousands of small scale maintainers, like folks maintaining a single driver or a single network protocol. Document our expectations and best practices. I'm hoping this doc will be particularly useful to set expectations with HW vendors. Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> --- Please consider this more of a draft than a statement of my opinion. IOW prefer suggesting edits over arguing about correctness, hope that makes sense. --- .../feature-and-driver-maintainers.rst | 159 ++++++++++++++++++ Documentation/maintainer/index.rst | 1 + 2 files changed, 160 insertions(+) create mode 100644 Documentation/maintainer/feature-and-driver-maintainers.rst diff --git a/Documentation/maintainer/feature-and-driver-maintainers.rst b/Documentation/maintainer/feature-and-driver-maintainers.rst new file mode 100644 index 000000000000..ee8ccc22b16a --- /dev/null +++ b/Documentation/maintainer/feature-and-driver-maintainers.rst @@ -0,0 +1,159 @@ +.. SPDX-License-Identifier: GPL-2.0 + +============================== +Feature and driver maintainers +============================== + +The term "maintainer" spans a very wide range of levels of engagement +from people handling patches and pull requests as almost a full time job +to people responsible for a small feature or a driver. + +Unlike most of the chapter, this section is meant for the latter (more +populous) group. It provides tips and describes the expectations and +responsibilities of maintainers of a small(ish) section of the code. + +Driver and alike most often do not have their own mailing lists and +git trees but instead send and review patches on the list of a larger +subsystem. + +Responsibilities +================ + +The amount of maintenance work is usually proportional to the size +and popularity of the code base. Small features and drivers should +require relatively small amount of care and feeding. Nonetheless +when the work does arrive (in form of patches which need review, +user bug reports etc.) it has to be acted upon very promptly. +Even when single driver only sees one patch a month, or a quarter, +a subsystem could well have a hundred such drivers. Subsystem +maintainers cannot afford to wait a long time to hear from reviewers. + +The exact expectations on the review time will vary by subsystem +from 1 day (e.g. networking) to a week in smaller subsystems. + +Mailing list participation +-------------------------- + +Linux kernel uses mailing lists as the primary form of communication. +Maintainers must be subscribed and follow the appropriate subsystem-wide +mailing list. Either by subscribing to the whole list or using more +modern, selective setup like +`lei <https://people.kernel.org/monsieuricon/lore-lei-part-1-getting-started>`_. + +Maintainers must know how to communicate on the list (plain text, no invasive +legal footers, no top posting, etc.) + +Reviews +------- + +Maintainers must review *all* patches touching exclusively their drivers, +no matter how trivial. If the patch is a tree wide change and modifies +multiple drivers - whether to provide a review is left to the maintainer. + +There should be multiple maintainers for any piece of code, an ``Acked-by`` +or ``Reviewed-by`` tag (or review comments) from a single maintainer is +enough to satisfy this requirement. + +If review process or validation for a particular change will take longer +than the expected review timeline for the subsystem, maintainer should +reply to the submission indicating that the work is being done, and when +to expect full results. + +Refactoring and core changes +---------------------------- + +Occasionally core code needs to be changed to improve the maintainability +of the kernel as a whole. Maintainers are expected to be present and +help guide and test changes to their code to fit the new infrastructure. + +Bug reports +----------- + +Maintainers must respond to and address bug reports. The bug reports +range from users reporting real life crashes, thru errors discovered +in fuzzing to reports of issues with the code found by static analysis +tools and new compiler warnings. + +Volunteer maintainers are only required to address bugs and regressions. +It is understood that due to lack of access to documentation and +implementation details they may not be able to solve all problems. + +Commercial vendors are expected to address all issues, on any reasonable +platform supported by the Linux kernel, as well as answer ordinary user +questions. There is no concept of product End-of-Life in the Linux kernel, +the support is required until the subsystem maintainer deletes the code. + +The volunteer vs commercial vendor distinction could be seen as roughly +corresponding to the *Maintained* and *Supported* statuses of the codebase +in the MAINTAINERS file. + +Selecting the maintainer +======================== + +The previous section described the expectations of the maintainer, +this section provides guidance on selecting one and decribes common +misconceptions. + +The author +---------- + +Most natural and common choice of a maintainer is the author of the code. +The author is intimately familiar with the code, so it is the best person +to take care of it on an ongoing basis. + +That said, being a maintainer is an active role. The MAINTAINERS file +is not a list of credits (in fact a separate CREDITS file exists), +it is a list of those who will actively help with the code. +If the author does not have the time, interest or ability to maintain +the code, a different maintainer must be selected. + +Multiple maintainers +-------------------- + +Modern best practices dictate that there should be at least two maintainers +for any piece of code, no matter how trivial. It spreads the burden, helps +people take vacations and prevents burnout, trains new members of +the community etc. etc. Even when there is clearly one perfect candidate, +another maintainer should be found. + +Maintainers must be human, however, it is not acceptable to add a mailing +list or a group email as a maintainer. Trust and understanding are the +foundation of kernel maintenance and one cannot build trust with a mailing +list. + +Corporate structures +-------------------- + +To an outsider the Linux kernel may resemble a hierarchical organization +with Linus as the CEO. While the code flows in a hierarchical fashion, +the corporate template does not apply here. Linux is an anarchy held +together by (rarely expressed) mutual respect, trust and convenience. + +All that is to say that managers almost never make good maintainers. +The maintainer position more closely matches an on-call rotation +than a position of power. + +The following characteristics of a person selected as a maintainer +are clear red flags: + + - unknown to the community, never sent an email to the list before + - did not author any of the code + - (when development is contracted) works for a company which paid + for the development rather than the company which did the work + +Non compliance +============== + +Subsystem maintainers may remove inactive maintainers from the MAINTAINERS +file. If the maintainer was a significant author or have played an important +role in the development of the code they should be moved to the CREDITS file. + +Removing an inactive maintainer should not be seen as a punitive action. +Having an inactive maintainer has a real cost as all developeres have +to remember to include the maintainers in discussions and subsystem +maintainers spend brain power figuring out how to solicit feedback. + +Subsystem maintainers may remove code for lacking maintenance. + +Subsystem maintainers may refuse accepting code from companies +which repeatedly neglected their maintainership duties. diff --git a/Documentation/maintainer/index.rst b/Documentation/maintainer/index.rst index 3e03283c144e..eeee27f8b18c 100644 --- a/Documentation/maintainer/index.rst +++ b/Documentation/maintainer/index.rst @@ -9,6 +9,7 @@ additions to this manual. .. toctree:: :maxdepth: 2 + feature-and-driver-maintainers configure-git rebasing-and-merging pull-requests -- 2.41.0
