Document what was discussed multiple times on list and various virtual / in-person conversations. guard() being okay in functions <= 20 LoC is a bit of my own invention. If the function is trivial it should be fine, but feel free to disagree :) We'll obviously revisit this guidance as time passes and we and other subsystems get more experience. Reviewed-by: Eric Dumazet <edumazet@xxxxxxxxxx> Reviewed-by: Nikolay Aleksandrov <razor@xxxxxxxxxxxxx> Reviewed-by: Andrew Lunn <andrew@xxxxxxx> Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> --- CC: horms@xxxxxxxxxx CC: corbet@xxxxxxx CC: linux-doc@xxxxxxxxxxxxxxx v2: - add sentence about revisiting later to commit msg - fix spelling v1: https://lore.kernel.org/20240829152025.3203577-1-kuba@xxxxxxxxxx --- Documentation/process/maintainer-netdev.rst | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/Documentation/process/maintainer-netdev.rst b/Documentation/process/maintainer-netdev.rst index 30d24eecdaaa..c9edf9e7362d 100644 --- a/Documentation/process/maintainer-netdev.rst +++ b/Documentation/process/maintainer-netdev.rst @@ -375,6 +375,22 @@ When working in existing code which uses nonstandard formatting make your code follow the most recent guidelines, so that eventually all code in the domain of netdev is in the preferred format. +Using device-managed and cleanup.h constructs +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + +Netdev remains skeptical about promises of all "auto-cleanup" APIs, +including even ``devm_`` helpers, historically. They are not the preferred +style of implementation, merely an acceptable one. + +Use of ``guard()`` is discouraged within any function longer than 20 lines, +``scoped_guard()`` is considered more readable. Using normal lock/unlock is +still (weakly) preferred. + +Low level cleanup constructs (such as ``__free()``) can be used when building +APIs and helpers, especially scoped iterators. However, direct use of +``__free()`` within networking core and drivers is discouraged. +Similar guidance applies to declaring variables mid-function. + Resending after review ~~~~~~~~~~~~~~~~~~~~~~ -- 2.46.0
