Re: [TECH TOPIC] Kernel documentation - update and future directions

[Mauro Carvalho Chehab <mchehab+huawei@kernel.org>]

Em Mon, 1 Sep 2025 18:52:30 +0100
Mark Brown <broonie@kernel.org> escreveu:

> On Mon, Sep 01, 2025 at 09:51:01AM -0700, Randy Dunlap wrote:
> 
> > Willy had a suggestion that we just make checking kernel-doc during
> > all .c builds a permanent feature instead of a W=1 option.
> > This helps, but still doesn't force 'make htmldocs' to be run.  
> 
> make htmldocs is rather slow:
> 
>   $ time make -j56 htmldocs
>   ...
>   make -j56 htmldocs  2355.99s user 141.33s system 158% cpu 26:14.86 total

Sphinx itself is not too fast, but we don't need to generate
htmldocs to get kernel-doc results.

On a Razen 9 7900, kernel-doc takes about 32 seconds.

It should be noticed that kernel-doc doesn't run in parallel. Python
still suffers for a global big lock (called GIL). My attempts to run in
parallel actually made kernel-doc slower, but this is changing: the
next Python version is planning to get rid of GIL. So, maybe within
a year we can re-add the patches to run it in parallel.

> and produces a bunch of warnings with current mainline it seems. 

True.

> That
> compares unfavourably with allmodconfig on this system:
> 
>   $ time make -j56 allmodconfig
>   ...
>   make -j56 allmodconfig  5.31s user 1.93s system 146% cpu 4.931 total
>   $ time make -j56
>   ...
>   make -j56  53468.11s user 4387.30s system 5084% cpu 18:57.77 total
> 
> and seems rather more likely to flag something for me.

32 seconds more, on the top of 53468.11s doesn't sound that much.


Thanks,
Mauro