Re: [PATCH net] docs: netdev: Document guidance on inline functions

[Simon Horman <horms@kernel.org>]

On Mon, Feb 03, 2025 at 08:53:12PM +0100, Mauro Carvalho Chehab wrote:
> Em Mon, 3 Feb 2025 20:50:39 +0100
> Mauro Carvalho Chehab <mchehab+huawei@kernel.org> escreveu:
> 
> > Em Mon, 03 Feb 2025 08:00:56 -0700
> > Jonathan Corbet <corbet@lwn.net> escreveu:
> > 
> > > Simon Horman <horms@kernel.org> writes:
> > > 
> > > > Document preference for non inline functions in .c files.
> > > > This has been the preference for as long as I can recall
> > > > and I was recently surprised to discover that it is undocumented.
> > > >
> > > > Reported-by: Alexandre Ferrieux <alexandre.ferrieux@gmail.com>
> > > > Closes: https://lore.kernel.org/all/9662e6fe-cc91-4258-aba1-ab5b016a041a@orange.com/
> > > > Signed-off-by: Simon Horman <horms@kernel.org>
> > > > ---
> > > >  Documentation/process/maintainer-netdev.rst | 11 +++++++++++
> > > >  1 file changed, 11 insertions(+)
> > > >
> > > > diff --git a/Documentation/process/maintainer-netdev.rst b/Documentation/process/maintainer-netdev.rst
> > > > index e497729525d5..1fbb8178b8cd 100644
> > > > --- a/Documentation/process/maintainer-netdev.rst
> > > > +++ b/Documentation/process/maintainer-netdev.rst
> > > > @@ -408,6 +408,17 @@ at a greater cost than the value of such clean-ups.
> > > >  
> > > >  Conversely, spelling and grammar fixes are not discouraged.
> > > >  
> > > > +Inline functions
> > > > +----------------
> > > > +
> > > > +The use of static inline functions in .c file is strongly discouraged
> > > > +unless there is a demonstrable reason for them, usually performance
> > > > +related. Rather, it is preferred to omit the inline keyword and allow the
> > > > +compiler to inline them as it sees fit.
> > 
> > You should probably point to chapter (12) of Documentation/process/coding-style.rst
> > where it mentions that inline for function prototypes and as a way to
> > replace macros are OK.
> 
> Heh, I hit enter too quickly...
> 
> I mean:
> 	"inline for function prototypes and as a way to replace macros on
> 	 header files (*.h) are OK."

Likewise, I responded to your previous message too quickly.

Yes, I agree something like that would be good.

> 
> > 
> > > > +
> > > > +This is a stricter requirement than that of the general Linux Kernel
> > > > +:ref:`Coding Style<codingstyle>`  
> > > 
> > > I have no objection to this change, but I do wonder if it does indeed
> > > belong in the central coding-style document.  I don't think anybody
> > > encourages use of "inline" these days...?
> > 
> > Indeed IMO this belongs to the coding style. I would place it close
> > to chapter (12) at Documentation/process/coding-style.rst.
> > 
> > Regards,
> > 
> > Thanks,
> > Mauro
> 
> 
> 
> Thanks,
> Mauro
>