| .. SPDX-License-Identifier: GPL-2.0 |
| |
| .. _netdev-FAQ: |
| |
| ========== |
| netdev FAQ |
| ========== |
| |
| 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/) and archives can be found below: |
| |
| - http://marc.info/?l=linux-netdev |
| - http://www.spinics.net/lists/netdev/ |
| |
| Aside from subsystems like that 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 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. |
| |
| IMPORTANT: Do not send new ``net-next`` content to netdev during the |
| period during which ``net-next`` tree is closed. |
| |
| 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. |
| |
| How do I indicate which tree (net vs. net-next) my patch should be in? |
| ---------------------------------------------------------------------- |
| Firstly, think whether you have a bug fix or new "next-like" content. |
| Then once decided, assuming that you use git, use the prefix flag, i.e. |
| :: |
| |
| 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. If you don't use git, then note the only magic |
| in the above is just the subject text of the outgoing e-mail, and you |
| can manually change it yourself with whatever MUA you are comfortable |
| with. |
| |
| I sent a patch and I'm wondering what happened to it - how can I tell whether it got merged? |
| -------------------------------------------------------------------------------------------- |
| 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. |
| |
| The above only says "Under Review". How can I find out more? |
| ------------------------------------------------------------- |
| Generally speaking, the patches get triaged quickly (in less than |
| 48h). So be patient. 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. |
| |
| I submitted multiple versions of the patch series. Should I directly update patchwork for the previous versions of these patch series? |
| -------------------------------------------------------------------------------------------------------------------------------------- |
| No, please don't interfere with the patch status on patchwork, 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. |
| |
| 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 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: stable@vger.kernel.org`` 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 |
| */ |
| |
| I am working in existing code that has the former comment style and not the latter. Should I submit new code in the former style or the latter? |
| ----------------------------------------------------------------------------------------------------------------------------------------------- |
| Make it the latter style, so that eventually all code in the domain |
| of netdev is of this 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 security@kernel.org 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? |
| ------------------------------------------------------------ |
| If your changes are against ``net-next``, the expectation is that you |
| have tested by layering your changes on top of ``net-next``. Ideally |
| you will have done run-time testing specific to your change, but at a |
| minimum, your changes should survive an ``allyesconfig`` and an |
| ``allmodconfig`` build without new warnings or failures. |
| |
| 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. |
