--- /dev/null
+.. submitting_patches:
+
+Contributing Code to DPDK
+=========================
+
+This document outlines the guidelines for submitting code to DPDK.
+
+The DPDK development process is modelled (loosely) on the Linux Kernel development model so it is worth reading the
+Linux kernel guide on submitting patches:
+`How to Get Your Change Into the Linux Kernel <http://www.kernel.org/doc/Documentation/SubmittingPatches>`_.
+The rationale for many of the DPDK guidelines is explained in greater detail in the kernel guidelines.
+
+
+The DPDK Development Process
+-----------------------------
+
+The DPDK development process has the following features:
+
+* The code is hosted in a public git repository.
+* There is a mailing list where developers submit patches.
+* There are maintainers for hierarchical components.
+* Patches are reviewed publicly on the mailing list.
+* Successfully reviewed patches are merged to the master branch of the repository.
+
+The mailing list for DPDK development is `dev@dpkg.org <http://dpdk.org/ml/archives/dev/>`_.
+Contributors will need to `register for the mailing list <http://dpdk.org/ml/listinfo/dev>`_ in order to submit patches.
+It is also worth registering for the DPDK `Patchwork <http://dpdk.org/dev/patchwxispork/project/dpdk/list/>`_
+
+The development process requires some familiarity with the ``git`` version control system.
+Refer to the `Pro Git Book <http://www.git-scm.com/book/>`_ for further information.
+
+
+Getting the Source Code
+-----------------------
+
+The source code can be cloned using either of the following::
+
+ git clone git://dpdk.org/dpdk
+
+ git clone http://dpdk.org/git/dpdk
+
+
+Make your Changes
+-----------------
+
+Make your planned changes in the cloned ``dpdk`` repo. Here are some guidelines and requirements:
+
+* Follow the :ref:`coding_style` guidelines.
+
+* If you add new files or directories you should add your name to the ``MAINTAINERS`` file.
+
+* New external functions should be added to the local ``version.map`` file.
+ See the :doc:`Guidelines for ABI policy and versioning </contributing/versioning>`.
+ New external functions should also be added in alphabetical order.
+
+* Important changes will require an addition to the release notes in ``doc/guides/rel_notes/``.
+ See the :ref:`Release Notes section of the Documentation Guidelines <doc_guidelines>` for details.
+
+* Test the compilation works with different targets, compilers and options, see :ref:`contrib_check_compilation`.
+
+* Don't break compilation between commits with forward dependencies in a patchset.
+ Each commit should compile on its own to allow for ``git bisect`` and continuous integration testing.
+
+* Add tests to the the ``app/test`` unit test framework where possible.
+
+* Add documentation, if relevant, in the form of Doxygen comments or a User Guide in RST format.
+ See the :ref:`Documentation Guidelines <doc_guidelines>`.
+
+Once the changes have been made you should commit them to your local repo.
+
+For small changes, that do not require specific explanations, it is better to keep things together in the
+same patch.
+Larger changes that require different explanations should be separated into logical patches in a patchset.
+A good way of thinking about whether a patch should be split is to consider whether the change could be
+applied without dependencies as a backport.
+
+As a guide to how patches should be structured run ``git log`` on similar files.
+
+
+Commit Messages: Subject Line
+-----------------------------
+
+The first, summary, line of the git commit message becomes the subject line of the patch email.
+Here are some guidelines for the summary line:
+
+* The summary line must capture the area and the impact of the change.
+
+* The summary line should be around 50 characters.
+
+* The summary line should be lowercase apart from acronyms.
+
+* It should be prefixed with the component name (use git log to check existing components).
+ For example::
+
+ ixgbe: fix offload config option name
+
+ config: increase max queues per port
+
+* Use the imperative of the verb (like instructions to the code base).
+
+* Don't add a period/full stop to the subject line or you will end up two in the patch name: ``dpdk_description..patch``.
+
+The actual email subject line should be prefixed by ``[PATCH]`` and the version, if greater than v1,
+for example: ``PATCH v2``.
+The is generally added by ``git send-email`` or ``git format-patch``, see below.
+
+If you are submitting an RFC draft of a feature you can use ``[RFC]`` instead of ``[PATCH]``.
+An RFC patch doesn't have to be complete.
+It is intended as a way of getting early feedback.
+
+
+Commit Messages: Body
+---------------------
+
+Here are some guidelines for the body of a commit message:
+
+* The body of the message should describe the issue being fixed or the feature being added.
+ It is important to provide enough information to allow a reviewer to understand the purpose of the patch.
+
+* When the change is obvious the body can be blank, apart from the signoff.
+
+* The commit message must end with a ``Signed-off-by:`` line which is added using::
+
+ git commit --signoff # or -s
+
+ The purpose of the signoff is explained in the
+ `Developer's Certificate of Origin <http://www.kernel.org/doc/Documentation/SubmittingPatches>`_
+ section of the Linux kernel guidelines.
+
+ .. Note::
+
+ All developers must ensure that they have read and understood the
+ Developer's Certificate of Origin section of the documentation prior
+ to applying the signoff and submitting a patch.
+
+* The signoff must be a real name and not an alias or nickname.
+ More than one signoff is allowed.
+
+* The text of the commit message should be wrapped at 72 characters.
+
+* When fixing a regression, it is a good idea to reference the id of the commit which introduced the bug.
+ You can generate the required text using the following git alias::
+
+ git config alias.fixline "log -1 --abbrev=12 --format='Fixes: %h (\"%s\")'"
+
+ The ``Fixes:`` line can then be added to the commit message::
+
+ doc: fix vhost sample parameter
+
+ Update the docs to reflect removed dev-index.
+
+ Fixes: 17b8320a3e11 ("vhost: remove index parameter")
+
+ Signed-off-by: Alex Smith <alex.smith@example.com>
+
+* When fixing an error or warning it is useful to add the error message and instructions on how to reproduce it.
+
+* Use correct capitalization, punctuation and spelling.
+
+In addition to the ``Signed-off-by:`` name the commit messages can also have one or more of the following:
+
+* ``Reported-by:`` The reporter of the issue.
+* ``Tested-by:`` The tester of the change.
+* ``Reviewed-by:`` The reviewer of the change.
+* ``Suggested-by:`` The person who suggested the change.
+* ``Acked-by:`` When a previous version of the patch was acked and the ack is still relevant.
+
+
+Creating Patches
+----------------
+
+It is possible to send patches directly from git but for new contributors it is recommended to generate the
+patches with ``git format-patch`` and then when everything looks okay, and the patches have been checked, to
+send them with ``git send-email``.
+
+Here are some examples of using ``git format-patch`` to generate patches:
+
+.. code-block:: console
+
+ # Generate a patch from the last commit.
+ git format-patch -1
+
+ # Generate a patch from the last 3 commits.
+ git format-patch -3
+
+ # Generate the patches in a directory.
+ git format-patch -3 -o ~/patch/
+
+ # Add a cover letter to explain a patchset.
+ git format-patch -3 -o ~/patch/ --cover-letter
+
+ # Add a prefix with a version number.
+ git format-patch -3 -o ~/patch/ -v 2
+
+
+Cover letters are useful for explaining a patchset and help to generate a logical threading to the patches.
+Smaller notes can be put inline in the patch after the ``---`` separator, for example::
+
+ Subject: [PATCH] fm10k/base: add FM10420 device ids
+
+ Add the device ID for Boulder Rapids and Atwood Channel to enable
+ drivers to support those devices.
+
+ Signed-off-by: Alex Smith <alex.smith@example.com>
+ ---
+
+ ADD NOTES HERE.
+
+ drivers/net/fm10k/base/fm10k_api.c | 6 ++++++
+ drivers/net/fm10k/base/fm10k_type.h | 6 ++++++
+ 2 files changed, 12 insertions(+)
+ ...
+
+Version 2 and later of a patchset should also include a short log of the changes so the reviewer knows what has changed.
+This can be added to the cover letter or the annotations.
+For example::
+
+ ---
+ v3:
+ * Fixed issued with version.map.
+
+ v2:
+ * Added i40e support.
+ * Renamed ethdev functions from rte_eth_ieee15888_*() to rte_eth_timesync_*()
+ since 802.1AS can be supported through the same interfaces.
+
+
+.. _contrib_checkpatch:
+
+Checking the Patches
+--------------------
+
+Patches should be checked for formatting and syntax issues using the ``checkpatches.sh`` script in the ``scripts``
+directory of the DPDK repo.
+This uses the Linux kernel development tool ``checkpatch.pl`` which can be obtained by cloning, and periodically,
+updating the Linux kernel sources.
+
+The path to the original Linux script must be set in the environment variable ``DPDK_CHECKPATCH_PATH``.
+This, and any other configuration variables required by the development tools, are loaded from the following
+files, in order of preference::
+
+ .develconfig
+ ~/.config/dpdk/devel.config
+ /etc/dpdk/devel.config.
+
+Once the environment variable the script can be run as follows::
+
+ scripts/checkpatches.sh ~/patch/
+
+The script usage is::
+
+ checkpatches.sh [-h] [-q] [-v] [patch1 [patch2] ...]]"
+
+Where:
+
+* ``-h``: help, usage.
+* ``-q``: quiet. Don't output anything for files without issues.
+* ``-v``: verbose.
+* ``patchX``: path to one or more patches.
+
+
+.. _contrib_check_compilation:
+
+Checking Compilation
+--------------------
+
+Compilation of patches and changes should be tested using the the ``test-build.sh`` script in the ``scripts``
+directory of the DPDK repo::
+
+ scripts/test-build.sh x86_64-native-linuxapp-gcc+next+shared+combined
+
+The script usage is::
+
+ test-build.sh [-h] [-jX] [-s] [config1 [config2] ...]]
+
+Where:
+
+* ``-h``: help, usage.
+* ``-jX``: use X parallel jobs in "make".
+* ``-s``: short test with only first config and without examples/doc.
+* ``config``: default config name plus config switches delimited with a ``+`` sign.
+
+Examples of configs are::
+
+ x86_64-native-linuxapp-gcc
+ x86_64-native-linuxapp-gcc+next+shared+combined
+ x86_64-native-linuxapp-gcc+shared+next
+ x86_64-native-linuxapp-clang+shared+combined
+ i686-native-linuxapp-gcc+combined
+
+The builds can be modifies via the following environmental variables:
+
+* ``DPDK_BUILD_TEST_CONFIGS`` (target1+option1+option2 target2)
+* ``DPDK_DEP_CFLAGS``
+* ``DPDK_DEP_LDFLAGS``
+* ``DPDK_DEP_MOFED`` (y/[n])
+* ``DPDK_DEP_PCAP`` (y/[n])
+* ``DPDK_NOTIFY`` (notify-send)
+
+These can be set from the command line or in the config files shown above in the :ref:`contrib_checkpatch`.
+
+The recommended configurations and options to test compilation prior to submitting patches are::
+
+ x86_64-native-linuxapp-gcc+shared+next
+ x86_64-native-linuxapp-clang+shared+combined
+ i686-native-linuxapp-gcc+combined
+
+ export DPDK_DEP_ZLIB=y
+ export DPDK_DEP_PCAP=y
+ export DPDK_DEP_SSL=y
+
+
+Sending Patches
+---------------
+
+Patches should be sent to the mailing list using ``git send-email``.
+You can configure an external SMTP with something like the following::
+
+ [sendemail]
+ smtpuser = name@domain.com
+ smtpserver = smtp.domain.com
+ smtpserverport = 465
+ smtpencryption = ssl
+
+See the `Git send-email <https://git-scm.com/docs/git-send-email>`_ documentation for more details.
+
+The patches should be sent to ``dev@dpdk.org``.
+If the patches are a change to existing files then you should send them TO the maintainer(s) and CC ``dev@dpdk.org``.
+The appropriate maintainer can be found in the ``MAINTAINERS`` file::
+
+ git send-email --to maintainer@some.org --cc dev@dpdk.org 000*.patch
+
+New additions can be sent without a maintainer::
+
+ git send-email --to dev@dpdk.org 000*.patch
+
+You can test the emails by sending it to yourself or with the ``--dry-run`` option.
+
+If the patch is in relation to a previous email thread you can add it to the same thread using the Message ID::
+
+ git send-email --to dev@dpdk.org --in-reply-to <1234-foo@bar.com> 000*.patch
+
+The Message ID can be found in the raw text of emails or at the top of each Patchwork patch,
+`for example <http://dpdk.org/dev/patchwork/patch/7646/>`_.
+Shallow threading (``--thread --no-chain-reply-to``) is preferred for a patch series.
+
+Once submitted your patches will appear on the mailing list and in Patchwork.
+
+Experienced committers may send patches directly with ``git send-email`` without the ``git format-patch`` step.
+The options ``--annotate`` and ``confirm = always`` are recommended for checking patches before sending.
+
+
+The Review Process
+------------------
+
+The more work you put into the previous steps the easier it will be to get a patch accepted.
+
+The general cycle for patch review and acceptance is:
+
+#. Submit the patch.
+
+#. Check the automatic test reports in the coming hours.
+
+#. Wait for review comments. While you are waiting review some other patches.
+
+#. Fix the review comments and submit a ``v n+1`` patchset::
+
+ git format-patch -3 -v 2
+
+#. Update Patchwork to mark your previous patches as "Superseded".
+
+#. If the patch is deemed suitable for merging by the relevant maintainer(s) or other developers they will ``ack``
+ the patch with an email that includes something like::
+
+ Acked-by: Alex Smith <alex.smith@example.com>
+
+ **Note**: When acking patches please remove as much of the text of the patch email as possible.
+ It is generally best to delete everything after the ``Signed-off-by:`` line.
+
+#. Having the patch ``Reviewed-by:`` and/or ``Tested-by:`` will also help the patch to be accepted.
+
+#. If the patch isn't deemed suitable based on being out of scope or conflicting with existing functionality
+ it may receive a ``nack``.
+ In this case you will need to make a more convincing technical argument in favor of your patches.
+
+#. In addition a patch will not be accepted if it doesn't address comments from a previous version with fixes or
+ valid arguments.
+
+#. Acked patches will be merged in the current or next merge window.
git.droids-corp.org / dpdk.git / commitdiff