Re: Suppressing native compilation (short and long term)

[Eli Zaretskii]

> From: Stefan Monnier <monnier@iro.umontreal.ca>
> Cc: Rob Browning <rlb@defaultvalue.org>,  tomas@tuxteam.de,
>   emacs-devel@gnu.org
> Date: Mon, 03 Oct 2022 12:39:44 -0400
> 
> > But Emacs does that all the time: there are many features that invoke
> > sub-processes and many more features that write to the disk.  I never
> > heard anyone complaining seriously about that, and I'm quite sure many
> > users don't even know which Emacs commands invoke subprocesses under
> > the hood.
> 
> FWIW, during the stealth jit-lock discussion, several people mentioned the
> battery impact.

Yes.  And jit-stealth is different, in that it takes a much longer
time for it to become quiet, because it works in small chinks, and
only when Emacs is actually idle.  JIT native-compilation is much
faster, and also uses several execution units of the CPU in parallel.

> And the issue is not subprocesses per se, but it's extra processing that
> happens outside of the control of the user.

How do you mean "outside of the control of the user"?  The user causes
it by loading a feature.  If no new features are loaded, no
native-compilation will happen.  How is that different from any other
command that uses a subprocess under the hood?

> > So I'm not sure these complaints are based on real problems.  Did
> > anyone compare the "sudden swamp of the CPU" caused by JIT native
> > compilation with what happens with other commands that invoke
> > subprocesses?  If so, did they present some quantitative data?
> 
> Probably not, no.  It's likely mostly a question of perception, so if we
> could make it completely invisible the "problem" would disappear :-)
> But the fact that lazy native compilation tends to pop up warnings (and
> to make matters worse, it does so ... without warning) makes it very
> much visible instead.

On my system, I don't see any warnings.