Friday, March 4, 2016

Branch strategy update

You may be noticed that there is no -gc branch in my git repositories from kernel 4.4. And yes, it is intended to be. As it's overhead to maintenance two branches and keep code changes stable on them. So here is the update for branch strategy

1. From 4.4 and so on, there will be only -vrq branch, no more -gc branch and vrq branch is considered stable.
2. There will be an -wip branch which will contain new code changes need to be tested before adding into -vrq branch.
3. The first release for a new kernel major version will contain *no new feature* code except the mainline scheduler sync-up changes. Hopefully this help to identify issues on new kernel release.
4. LTS (long term support) branch. For any kind of reasons,  I think LTS branch is needed as they runs for years at lease after the next LTS kernel comes out. I will try best to back-port  new code changes to LTS branch and see how it helps with people who stick on it. The first LTS branch is linux-4.4.y-vrq.

BR Alfred


  1. Mmmh... Does kernel 4.5 introduce so many changes? I don't see patches for BFQ I/O, Tuxonice and BFS/VRQ surfacing.

    Alfred, keep up your good work, I am and probably many others are looking forward to your patch(es). :-)

    BR Manuel Krause

    1. Busy at work and have been sick for weeks b/c the unlovely weather, :)
      There is not much changes for scheduler code changes in 4.5, the first version of bfs has been booted ok last week, but just got too few free time to continue the work.
      As there is a long weekend this week, I'll see if I can finish the sync-up work and release the first version for 4.5.

      BR Alfred

  2. With 4.5 there were cgroups v2 introduced, and I think BFQ and BFS should honor it. And if I remember correct, cgroups v1 needs a long time for BFS, and I think Con said, that some features are still missing/supported (aka not needed ;) ). But maybe Alfred has proper info than me?

    Regards sysitos

  3. Dear Alfred,
    I hope that you are/get healthy again, to provide us with your new patch series for kernel 4.5, soon!

    My best wishes and regards,
    Manuel Krause