Re: Default of jit-lock-stealth-time

[David Kastrup <dak@gnu.org>]

Richard Stallman <rms@gnu.org> writes:

>     Regardless of the system load: the load may be low at the moment
>     _exactly_ because the user terminated all processes that would disturb
>     the interactivity of his current work, and I think it a mistake that
>     Emacs considers the CPU fit for grabbing for its own purposes unless
>     the user _explicitly_ asked for it.
>
> Stealth fontification is intended to stop whenever the user types a
> character.  So why would it interfere with the "interactivity" of
> Emacs commands?

Who is talking about the interactivity of Emacs?  Emacs might not be
the only application on the system.

> Is there a bug which prevents stealth fontification from stopping
> quickly?

Actually, yes.  There are font-locking situations in stealth
fontification that don't finish immediately and even cause quite a bit
of sluggishness for Emacs itself.

But even apart from that, even if all font lock patterns for all modes
worked perfectly, this causes _considerable_ power drain whenever I
restart Emacs, reloading all files using desktop.el.  The fan goes on,
blinking gets sluggish, and I notice that Emacs is eating my batteries
_again_.

Even if this worked perfectly (which it doesn't), we have no business
eating "stealth CPU" power in the default configuration since it is
near impossible for the user (heck, I am not exactly naive, and it was
impossible for me to find this on my own without an explicit pointer
after an error report) to guess just _what_ is eating her CPU.

-- 
David Kastrup, Kriemhildstr. 15, 44793 Bochum