From: Hans de Goede on gitlab.com https://gitlab.com/cki-project/kernel-ark/-/merge_requests/2832#note_1684783523 So @hpa1 created this script at my request. Looking at the discussions here it seems there are 2 separate discussion points: 1. Why use a script 2. Why disable these drivers I've just answered 2. in the other thread below, so let me try to answer 1. here. The current way the redhat/configs/ dir / config-system works does not lend itself well to easily make big changes and it also does not really match with the mental model which I have of the kind of changes which I would like to make to reduce Fedora's kernel size. I asked Kate to make this script because I basically want to be able to specify an allow list for drivers in a certain subdir (e.g. drivers/iio/accel) . I have done a lot of work on x86 tablets so I know exactly which drivers are actually necessary and which ones are not. So to me the primary purpose of this script is to actually be able to express what I want: "only build these drivers" in a format which actually matches what I'm trying to express and then have this script translate this to the less then user-friendly redhat/configs/ "config-system" . The current x86_accel_allow file really is just the beginning and once this is in place I plan to add quite a few more, for starters at least for all the other subdirs under drivers/iio and also for drivers/regulators. Where there will be a single squashed commit for e.g. adding the new x86_iio_light allow file together with the results of running the script with that file for the first time. To me the script is just a way of being able to focus any time spend on this on what actually matters: "which drivers should stay enabled?" without having to spend a lot of time on the mechanism of then implementing the change once that question is answered. Now to answer the various rightfully asked questions: > How is the allow list maintained? Where is the information pulled from? I'm afraid the answer to that is maintained manually and the information comes from a domain expert. IOW the information comes from my brain (a mix of disabling spi/i2c drivers without an acpi_match_table + being aware of some exceptions). I do actually hope that having x86_disable_unused_drivers.py available may also help with experts of other parts of the kernel doing something similar for e.g. nic / switch drivers. > The script itself is not a bad idea, but it can not be run again after the next merge window unless someone, or ideally some automated process, can update the allow_list. Right the plan here is for separate subdir allow-list files to have a maintainer (me in this case) who say after rc2 is out runs the script on kernel-ark/os-build. Followed by manually looking at what the script disables and then either submits the results or updates the allow_list (or a mix of both). Since the upstream Kconfig does not really attempt to limit which drivers can be build on an arch to hw which are actually used in designs for that arch. And if that allow-list maintainer somehow misses a cycle then we just move forward as before with some extra driver enabled and hopefully the next cycle they do get around to it and also disable some drivers which were enabled unnecessarily in the previous cycle. Basically the idea behind the script is to make it easier to not just make this size reduction a one time thing, but to also actually maintain this over time. But this will still need *active *maintenance, with as fallback the old model of just enabling all the drivers. -- _______________________________________________ kernel mailing list -- kernel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to kernel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@xxxxxxxxxxxxxxxxxxxxxxx Do not reply to spam, report it: https://pagure.io/fedora-infrastructure/new_issue
