1.. SPDX-License-Identifier: GPL-2.0 2 3.. _netdev-FAQ: 4 5========== 6netdev FAQ 7========== 8 9Q: What is netdev? 10------------------ 11A: It is a mailing list for all network-related Linux stuff. This 12includes anything found under net/ (i.e. core code like IPv6) and 13drivers/net (i.e. hardware specific drivers) in the Linux source tree. 14 15Note that some subsystems (e.g. wireless drivers) which have a high 16volume of traffic have their own specific mailing lists. 17 18The netdev list is managed (like many other Linux mailing lists) through 19VGER (http://vger.kernel.org/) and archives can be found below: 20 21- http://marc.info/?l=linux-netdev 22- http://www.spinics.net/lists/netdev/ 23 24Aside from subsystems like that mentioned above, all network-related 25Linux development (i.e. RFC, review, comments, etc.) takes place on 26netdev. 27 28Q: How do the changes posted to netdev make their way into Linux? 29----------------------------------------------------------------- 30A: There are always two trees (git repositories) in play. Both are 31driven by David Miller, the main network maintainer. There is the 32``net`` tree, and the ``net-next`` tree. As you can probably guess from 33the names, the ``net`` tree is for fixes to existing code already in the 34mainline tree from Linus, and ``net-next`` is where the new code goes 35for the future release. You can find the trees here: 36 37- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git 38- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git 39 40Q: How often do changes from these trees make it to the mainline Linus tree? 41---------------------------------------------------------------------------- 42A: To understand this, you need to know a bit of background information on 43the cadence of Linux development. Each new release starts off with a 44two week "merge window" where the main maintainers feed their new stuff 45to Linus for merging into the mainline tree. After the two weeks, the 46merge window is closed, and it is called/tagged ``-rc1``. No new 47features get mainlined after this -- only fixes to the rc1 content are 48expected. After roughly a week of collecting fixes to the rc1 content, 49rc2 is released. This repeats on a roughly weekly basis until rc7 50(typically; sometimes rc6 if things are quiet, or rc8 if things are in a 51state of churn), and a week after the last vX.Y-rcN was done, the 52official vX.Y is released. 53 54Relating that to netdev: At the beginning of the 2-week merge window, 55the ``net-next`` tree will be closed - no new changes/features. The 56accumulated new content of the past ~10 weeks will be passed onto 57mainline/Linus via a pull request for vX.Y -- at the same time, the 58``net`` tree will start accumulating fixes for this pulled content 59relating to vX.Y 60 61An announcement indicating when ``net-next`` has been closed is usually 62sent to netdev, but knowing the above, you can predict that in advance. 63 64IMPORTANT: Do not send new ``net-next`` content to netdev during the 65period during which ``net-next`` tree is closed. 66 67Shortly after the two weeks have passed (and vX.Y-rc1 is released), the 68tree for ``net-next`` reopens to collect content for the next (vX.Y+1) 69release. 70 71If you aren't subscribed to netdev and/or are simply unsure if 72``net-next`` has re-opened yet, simply check the ``net-next`` git 73repository link above for any new networking-related commits. You may 74also check the following website for the current status: 75 76 http://vger.kernel.org/~davem/net-next.html 77 78The ``net`` tree continues to collect fixes for the vX.Y content, and is 79fed back to Linus at regular (~weekly) intervals. Meaning that the 80focus for ``net`` is on stabilization and bug fixes. 81 82Finally, the vX.Y gets released, and the whole cycle starts over. 83 84Q: So where are we now in this cycle? 85 86Load the mainline (Linus) page here: 87 88 https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 89 90and note the top of the "tags" section. If it is rc1, it is early in 91the dev cycle. If it was tagged rc7 a week ago, then a release is 92probably imminent. 93 94Q: How do I indicate which tree (net vs. net-next) my patch should be in? 95------------------------------------------------------------------------- 96A: Firstly, think whether you have a bug fix or new "next-like" content. 97Then once decided, assuming that you use git, use the prefix flag, i.e. 98:: 99 100 git format-patch --subject-prefix='PATCH net-next' start..finish 101 102Use ``net`` instead of ``net-next`` (always lower case) in the above for 103bug-fix ``net`` content. If you don't use git, then note the only magic 104in the above is just the subject text of the outgoing e-mail, and you 105can manually change it yourself with whatever MUA you are comfortable 106with. 107 108Q: I sent a patch and I'm wondering what happened to it? 109-------------------------------------------------------- 110Q: How can I tell whether it got merged? 111A: Start by looking at the main patchworks queue for netdev: 112 113 https://patchwork.kernel.org/project/netdevbpf/list/ 114 115The "State" field will tell you exactly where things are at with your 116patch. 117 118Q: The above only says "Under Review". How can I find out more? 119---------------------------------------------------------------- 120A: Generally speaking, the patches get triaged quickly (in less than 12148h). So be patient. Asking the maintainer for status updates on your 122patch is a good way to ensure your patch is ignored or pushed to the 123bottom of the priority list. 124 125Q: I submitted multiple versions of the patch series 126---------------------------------------------------- 127Q: should I directly update patchwork for the previous versions of these 128patch series? 129A: No, please don't interfere with the patch status on patchwork, leave 130it to the maintainer to figure out what is the most recent and current 131version that should be applied. If there is any doubt, the maintainer 132will reply and ask what should be done. 133 134Q: I made changes to only a few patches in a patch series should I resend only those changed? 135--------------------------------------------------------------------------------------------- 136A: No, please resend the entire patch series and make sure you do number your 137patches such that it is clear this is the latest and greatest set of patches 138that can be applied. 139 140Q: 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? 141------------------------------------------------------------------------------------------------------------------------------------------- 142A: There is no revert possible, once it is pushed out, it stays like that. 143Please send incremental versions on top of what has been merged in order to fix 144the patches the way they would look like if your latest patch series was to be 145merged. 146 147Q: Are there special rules regarding stable submissions on netdev? 148--------------------------------------------------------------- 149While it used to be the case that netdev submissions were not supposed 150to carry explicit ``CC: stable@vger.kernel.org`` tags that is no longer 151the case today. Please follow the standard stable rules in 152:ref:`Documentation/process/stable-kernel-rules.rst <stable_kernel_rules>`, 153and make sure you include appropriate Fixes tags! 154 155Q: Is the comment style convention different for the networking content? 156------------------------------------------------------------------------ 157A: Yes, in a largely trivial way. Instead of this:: 158 159 /* 160 * foobar blah blah blah 161 * another line of text 162 */ 163 164it is requested that you make it look like this:: 165 166 /* foobar blah blah blah 167 * another line of text 168 */ 169 170Q: I am working in existing code that has the former comment style and not the latter. 171-------------------------------------------------------------------------------------- 172Q: Should I submit new code in the former style or the latter? 173A: Make it the latter style, so that eventually all code in the domain 174of netdev is of this format. 175 176Q: I found a bug that might have possible security implications or similar. 177--------------------------------------------------------------------------- 178Q: Should I mail the main netdev maintainer off-list?** 179A: No. The current netdev maintainer has consistently requested that 180people use the mailing lists and not reach out directly. If you aren't 181OK with that, then perhaps consider mailing security@kernel.org or 182reading about http://oss-security.openwall.org/wiki/mailing-lists/distros 183as possible alternative mechanisms. 184 185Q: What level of testing is expected before I submit my change? 186--------------------------------------------------------------- 187A: If your changes are against ``net-next``, the expectation is that you 188have tested by layering your changes on top of ``net-next``. Ideally 189you will have done run-time testing specific to your change, but at a 190minimum, your changes should survive an ``allyesconfig`` and an 191``allmodconfig`` build without new warnings or failures. 192 193Q: How do I post corresponding changes to user space components? 194---------------------------------------------------------------- 195A: User space code exercising kernel features should be posted 196alongside kernel patches. This gives reviewers a chance to see 197how any new interface is used and how well it works. 198 199When user space tools reside in the kernel repo itself all changes 200should generally come as one series. If series becomes too large 201or the user space project is not reviewed on netdev include a link 202to a public repo where user space patches can be seen. 203 204In case user space tooling lives in a separate repository but is 205reviewed on netdev (e.g. patches to `iproute2` tools) kernel and 206user space patches should form separate series (threads) when posted 207to the mailing list, e.g.:: 208 209 [PATCH net-next 0/3] net: some feature cover letter 210 └─ [PATCH net-next 1/3] net: some feature prep 211 └─ [PATCH net-next 2/3] net: some feature do it 212 └─ [PATCH net-next 3/3] selftest: net: some feature 213 214 [PATCH iproute2-next] ip: add support for some feature 215 216Posting as one thread is discouraged because it confuses patchwork 217(as of patchwork 2.2.2). 218 219Q: Any other tips to help ensure my net/net-next patch gets OK'd? 220----------------------------------------------------------------- 221A: Attention to detail. Re-read your own work as if you were the 222reviewer. You can start with using ``checkpatch.pl``, perhaps even with 223the ``--strict`` flag. But do not be mindlessly robotic in doing so. 224If your change is a bug fix, make sure your commit log indicates the 225end-user visible symptom, the underlying reason as to why it happens, 226and then if necessary, explain why the fix proposed is the best way to 227get things done. Don't mangle whitespace, and as is common, don't 228mis-indent function arguments that span multiple lines. If it is your 229first patch, mail it to yourself so you can test apply it to an 230unpatched tree to confirm infrastructure didn't mangle it. 231 232Finally, go back and read 233:ref:`Documentation/process/submitting-patches.rst <submittingpatches>` 234to be sure you are not repeating some common mistake documented there. 235