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

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

On Mon, Sep 01, 2025 at 07:52:01PM +0100, Mark Brown wrote:
> On Mon, Sep 01, 2025 at 08:46:35PM +0200, Mauro Carvalho Chehab wrote:
> 
> > 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.
> 
> It'll take a lot longer for that to filter out to people's machines, for
> example I'm running Debian stable on my desktop and I know a lot of
> people have Ubuntu LTS.
> 
> > > 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.
> 
> Yeah, if it was of that sort of order, ran clean with mainline and could
> be checked automatically it'd be a lot more viable.

If you run:

	 kernel-doc . --none -Wall

You won't have troubles with Sphinx slowness. It would be worth timing
it on you machine and see how much time it takes to run. Probably
the run time depends a little bit on the Python version. Not sure how
much optimization it got(*).

(*) Here, I use Fedora 42, so it is a recent Python version, but I
    gues even on Debian and Ubuntu LTS, if python version affects,
    you can install a newer version from the official packages.

-- 
Thanks,
Mauro