Re: bug-reference-prog-mode slows down CC Mode's scrolling by ~7%

[Eli Zaretskii]

> Date: Mon, 6 Sep 2021 10:46:48 +0000
> Cc: monnier@iro.umontreal.ca, emacs-devel@gnu.org
> From: Alan Mackenzie <acm@muc.de>
> 
> I think the optimal size for jit-lock-chunk-size is a little over how
> much text fits in a window.  That way, an entire window can be fontified
> in a single chunk, minimising overhead.  However, much more than that,
> and the fontification is less JIT, more like fontifying large chunks of
> a buffer just in case.
> 
> So, I propose a default value of 2000.  Approximately 1700 characters of
> xdisp.c fit into a default sized GUI window.

Not here.  I only get 1300.

In any case, can we please perform the single-windowful scroll
benchmark before making the decision?  Doing this stuff from intuition
is known to be a bad idea.

> +The optimum value is a little over the typical number of buffer
> +characters which fit in a window."

"in a typical window", probably, since not all windows are created
equal, and in general the frames aren't always single-windowed.