forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
321 lines
14 KiB
321 lines
14 KiB
.. SPDX-License-Identifier: GPL-2.0 |
|
|
|
.. _netdev-FAQ: |
|
|
|
========== |
|
netdev FAQ |
|
========== |
|
|
|
tl;dr |
|
----- |
|
|
|
- designate your patch to a tree - ``[PATCH net]`` or ``[PATCH net-next]`` |
|
- for fixes the ``Fixes:`` tag is required, regardless of the tree |
|
- don't post large series (> 15 patches), break them up |
|
- don't repost your patches within one 24h period |
|
- reverse xmas tree |
|
|
|
What is netdev? |
|
--------------- |
|
It is a mailing list for all network-related Linux stuff. This |
|
includes anything found under net/ (i.e. core code like IPv6) and |
|
drivers/net (i.e. hardware specific drivers) in the Linux source tree. |
|
|
|
Note that some subsystems (e.g. wireless drivers) which have a high |
|
volume of traffic have their own specific mailing lists. |
|
|
|
The netdev list is managed (like many other Linux mailing lists) through |
|
VGER (http://vger.kernel.org/) with archives available at |
|
https://lore.kernel.org/netdev/ |
|
|
|
Aside from subsystems like those mentioned above, all network-related |
|
Linux development (i.e. RFC, review, comments, etc.) takes place on |
|
netdev. |
|
|
|
How do the changes posted to netdev make their way into Linux? |
|
-------------------------------------------------------------- |
|
There are always two trees (git repositories) in play. Both are |
|
driven by David Miller, the main network maintainer. There is the |
|
``net`` tree, and the ``net-next`` tree. As you can probably guess from |
|
the names, the ``net`` tree is for fixes to existing code already in the |
|
mainline tree from Linus, and ``net-next`` is where the new code goes |
|
for the future release. You can find the trees here: |
|
|
|
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git |
|
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git |
|
|
|
How do I indicate which tree (net vs. net-next) my patch should be in? |
|
---------------------------------------------------------------------- |
|
To help maintainers and CI bots you should explicitly mark which tree |
|
your patch is targeting. Assuming that you use git, use the prefix |
|
flag:: |
|
|
|
git format-patch --subject-prefix='PATCH net-next' start..finish |
|
|
|
Use ``net`` instead of ``net-next`` (always lower case) in the above for |
|
bug-fix ``net`` content. |
|
|
|
How often do changes from these trees make it to the mainline Linus tree? |
|
------------------------------------------------------------------------- |
|
To understand this, you need to know a bit of background information on |
|
the cadence of Linux development. Each new release starts off with a |
|
two week "merge window" where the main maintainers feed their new stuff |
|
to Linus for merging into the mainline tree. After the two weeks, the |
|
merge window is closed, and it is called/tagged ``-rc1``. No new |
|
features get mainlined after this -- only fixes to the rc1 content are |
|
expected. After roughly a week of collecting fixes to the rc1 content, |
|
rc2 is released. This repeats on a roughly weekly basis until rc7 |
|
(typically; sometimes rc6 if things are quiet, or rc8 if things are in a |
|
state of churn), and a week after the last vX.Y-rcN was done, the |
|
official vX.Y is released. |
|
|
|
Relating that to netdev: At the beginning of the 2-week merge window, |
|
the ``net-next`` tree will be closed - no new changes/features. The |
|
accumulated new content of the past ~10 weeks will be passed onto |
|
mainline/Linus via a pull request for vX.Y -- at the same time, the |
|
``net`` tree will start accumulating fixes for this pulled content |
|
relating to vX.Y |
|
|
|
An announcement indicating when ``net-next`` has been closed is usually |
|
sent to netdev, but knowing the above, you can predict that in advance. |
|
|
|
.. warning:: |
|
Do not send new ``net-next`` content to netdev during the |
|
period during which ``net-next`` tree is closed. |
|
|
|
RFC patches sent for review only are obviously welcome at any time |
|
(use ``--subject-prefix='RFC net-next'`` with ``git format-patch``). |
|
|
|
Shortly after the two weeks have passed (and vX.Y-rc1 is released), the |
|
tree for ``net-next`` reopens to collect content for the next (vX.Y+1) |
|
release. |
|
|
|
If you aren't subscribed to netdev and/or are simply unsure if |
|
``net-next`` has re-opened yet, simply check the ``net-next`` git |
|
repository link above for any new networking-related commits. You may |
|
also check the following website for the current status: |
|
|
|
http://vger.kernel.org/~davem/net-next.html |
|
|
|
The ``net`` tree continues to collect fixes for the vX.Y content, and is |
|
fed back to Linus at regular (~weekly) intervals. Meaning that the |
|
focus for ``net`` is on stabilization and bug fixes. |
|
|
|
Finally, the vX.Y gets released, and the whole cycle starts over. |
|
|
|
So where are we now in this cycle? |
|
---------------------------------- |
|
|
|
Load the mainline (Linus) page here: |
|
|
|
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git |
|
|
|
and note the top of the "tags" section. If it is rc1, it is early in |
|
the dev cycle. If it was tagged rc7 a week ago, then a release is |
|
probably imminent. If the most recent tag is a final release tag |
|
(without an ``-rcN`` suffix) - we are most likely in a merge window |
|
and ``net-next`` is closed. |
|
|
|
How can I tell the status of a patch I've sent? |
|
----------------------------------------------- |
|
Start by looking at the main patchworks queue for netdev: |
|
|
|
https://patchwork.kernel.org/project/netdevbpf/list/ |
|
|
|
The "State" field will tell you exactly where things are at with your |
|
patch. Patches are indexed by the ``Message-ID`` header of the emails |
|
which carried them so if you have trouble finding your patch append |
|
the value of ``Message-ID`` to the URL above. |
|
|
|
How long before my patch is accepted? |
|
------------------------------------- |
|
Generally speaking, the patches get triaged quickly (in less than |
|
48h). But be patient, if your patch is active in patchwork (i.e. it's |
|
listed on the project's patch list) the chances it was missed are close to zero. |
|
Asking the maintainer for status updates on your |
|
patch is a good way to ensure your patch is ignored or pushed to the |
|
bottom of the priority list. |
|
|
|
Should I directly update patchwork state of my own patches? |
|
----------------------------------------------------------- |
|
It may be tempting to help the maintainers and update the state of your |
|
own patches when you post a new version or spot a bug. Please do not do that. |
|
Interfering with the patch status on patchwork will only cause confusion. Leave |
|
it to the maintainer to figure out what is the most recent and current |
|
version that should be applied. If there is any doubt, the maintainer |
|
will reply and ask what should be done. |
|
|
|
How do I divide my work into patches? |
|
------------------------------------- |
|
|
|
Put yourself in the shoes of the reviewer. Each patch is read separately |
|
and therefore should constitute a comprehensible step towards your stated |
|
goal. |
|
|
|
Avoid sending series longer than 15 patches. Larger series takes longer |
|
to review as reviewers will defer looking at it until they find a large |
|
chunk of time. A small series can be reviewed in a short time, so Maintainers |
|
just do it. As a result, a sequence of smaller series gets merged quicker and |
|
with better review coverage. Re-posting large series also increases the mailing |
|
list traffic. |
|
|
|
I made changes to only a few patches in a patch series should I resend only those changed? |
|
------------------------------------------------------------------------------------------ |
|
No, please resend the entire patch series and make sure you do number your |
|
patches such that it is clear this is the latest and greatest set of patches |
|
that can be applied. |
|
|
|
I have received review feedback, when should I post a revised version of the patches? |
|
------------------------------------------------------------------------------------- |
|
Allow at least 24 hours to pass between postings. This will ensure reviewers |
|
from all geographical locations have a chance to chime in. Do not wait |
|
too long (weeks) between postings either as it will make it harder for reviewers |
|
to recall all the context. |
|
|
|
Make sure you address all the feedback in your new posting. Do not post a new |
|
version of the code if the discussion about the previous version is still |
|
ongoing, unless directly instructed by a reviewer. |
|
|
|
I submitted multiple versions of a patch series and it looks like a version other than the last one has been accepted, what should I do? |
|
---------------------------------------------------------------------------------------------------------------------------------------- |
|
There is no revert possible, once it is pushed out, it stays like that. |
|
Please send incremental versions on top of what has been merged in order to fix |
|
the patches the way they would look like if your latest patch series was to be |
|
merged. |
|
|
|
Are there special rules regarding stable submissions on netdev? |
|
--------------------------------------------------------------- |
|
While it used to be the case that netdev submissions were not supposed |
|
to carry explicit ``CC: [email protected]`` tags that is no longer |
|
the case today. Please follow the standard stable rules in |
|
:ref:`Documentation/process/stable-kernel-rules.rst <stable_kernel_rules>`, |
|
and make sure you include appropriate Fixes tags! |
|
|
|
Is the comment style convention different for the networking content? |
|
--------------------------------------------------------------------- |
|
Yes, in a largely trivial way. Instead of this:: |
|
|
|
/* |
|
* foobar blah blah blah |
|
* another line of text |
|
*/ |
|
|
|
it is requested that you make it look like this:: |
|
|
|
/* foobar blah blah blah |
|
* another line of text |
|
*/ |
|
|
|
What is "reverse xmas tree"? |
|
---------------------------- |
|
|
|
Netdev has a convention for ordering local variables in functions. |
|
Order the variable declaration lines longest to shortest, e.g.:: |
|
|
|
struct scatterlist *sg; |
|
struct sk_buff *skb; |
|
int err, i; |
|
|
|
If there are dependencies between the variables preventing the ordering |
|
move the initialization out of line. |
|
|
|
I am working in existing code which uses non-standard formatting. Which formatting should I use? |
|
------------------------------------------------------------------------------------------------ |
|
Make your code follow the most recent guidelines, so that eventually all code |
|
in the domain of netdev is in the preferred format. |
|
|
|
I found a bug that might have possible security implications or similar. Should I mail the main netdev maintainer off-list? |
|
--------------------------------------------------------------------------------------------------------------------------- |
|
No. The current netdev maintainer has consistently requested that |
|
people use the mailing lists and not reach out directly. If you aren't |
|
OK with that, then perhaps consider mailing [email protected] or |
|
reading about http://oss-security.openwall.org/wiki/mailing-lists/distros |
|
as possible alternative mechanisms. |
|
|
|
What level of testing is expected before I submit my change? |
|
------------------------------------------------------------ |
|
At the very minimum your changes must survive an ``allyesconfig`` and an |
|
``allmodconfig`` build with ``W=1`` set without new warnings or failures. |
|
|
|
Ideally you will have done run-time testing specific to your change, |
|
and the patch series contains a set of kernel selftest for |
|
``tools/testing/selftests/net`` or using the KUnit framework. |
|
|
|
You are expected to test your changes on top of the relevant networking |
|
tree (``net`` or ``net-next``) and not e.g. a stable tree or ``linux-next``. |
|
|
|
How do I post corresponding changes to user space components? |
|
------------------------------------------------------------- |
|
User space code exercising kernel features should be posted |
|
alongside kernel patches. This gives reviewers a chance to see |
|
how any new interface is used and how well it works. |
|
|
|
When user space tools reside in the kernel repo itself all changes |
|
should generally come as one series. If series becomes too large |
|
or the user space project is not reviewed on netdev include a link |
|
to a public repo where user space patches can be seen. |
|
|
|
In case user space tooling lives in a separate repository but is |
|
reviewed on netdev (e.g. patches to ``iproute2`` tools) kernel and |
|
user space patches should form separate series (threads) when posted |
|
to the mailing list, e.g.:: |
|
|
|
[PATCH net-next 0/3] net: some feature cover letter |
|
└─ [PATCH net-next 1/3] net: some feature prep |
|
└─ [PATCH net-next 2/3] net: some feature do it |
|
└─ [PATCH net-next 3/3] selftest: net: some feature |
|
|
|
[PATCH iproute2-next] ip: add support for some feature |
|
|
|
Posting as one thread is discouraged because it confuses patchwork |
|
(as of patchwork 2.2.2). |
|
|
|
Can I reproduce the checks from patchwork on my local machine? |
|
-------------------------------------------------------------- |
|
|
|
Checks in patchwork are mostly simple wrappers around existing kernel |
|
scripts, the sources are available at: |
|
|
|
https://github.com/kuba-moo/nipa/tree/master/tests |
|
|
|
Running all the builds and checks locally is a pain, can I post my patches and have the patchwork bot validate them? |
|
-------------------------------------------------------------------------------------------------------------------- |
|
|
|
No, you must ensure that your patches are ready by testing them locally |
|
before posting to the mailing list. The patchwork build bot instance |
|
gets overloaded very easily and netdev@vger really doesn't need more |
|
traffic if we can help it. |
|
|
|
netdevsim is great, can I extend it for my out-of-tree tests? |
|
------------------------------------------------------------- |
|
|
|
No, ``netdevsim`` is a test vehicle solely for upstream tests. |
|
(Please add your tests under ``tools/testing/selftests/``.) |
|
|
|
We also give no guarantees that ``netdevsim`` won't change in the future |
|
in a way which would break what would normally be considered uAPI. |
|
|
|
Is netdevsim considered a "user" of an API? |
|
------------------------------------------- |
|
|
|
Linux kernel has a long standing rule that no API should be added unless |
|
it has a real, in-tree user. Mock-ups and tests based on ``netdevsim`` are |
|
strongly encouraged when adding new APIs, but ``netdevsim`` in itself |
|
is **not** considered a use case/user. |
|
|
|
Any other tips to help ensure my net/net-next patch gets OK'd? |
|
-------------------------------------------------------------- |
|
Attention to detail. Re-read your own work as if you were the |
|
reviewer. You can start with using ``checkpatch.pl``, perhaps even with |
|
the ``--strict`` flag. But do not be mindlessly robotic in doing so. |
|
If your change is a bug fix, make sure your commit log indicates the |
|
end-user visible symptom, the underlying reason as to why it happens, |
|
and then if necessary, explain why the fix proposed is the best way to |
|
get things done. Don't mangle whitespace, and as is common, don't |
|
mis-indent function arguments that span multiple lines. If it is your |
|
first patch, mail it to yourself so you can test apply it to an |
|
unpatched tree to confirm infrastructure didn't mangle it. |
|
|
|
Finally, go back and read |
|
:ref:`Documentation/process/submitting-patches.rst <submittingpatches>` |
|
to be sure you are not repeating some common mistake documented there.
|
|
|