bug#40384: 26.3; [Windows10] variable-pitch-mode is slow to redraw

[Eli Zaretskii]

> From: <gennady.uraltsev@gmail.com>
> Cc: <40384@debbugs.gnu.org>
> Date: Thu, 2 Apr 2020 18:29:07 -0400
> 
> By default the font that gets used is
> 
>           display: by this font (glyph code)
>  
> uniscribe:-outline-Arial-normal-normal-normal-sans-20-*-*-*-p-*-iso8859-1
> (#x03)

That's the same font I get, but I see no slowdown.

Thanks for the profile, it says that somehow redrawing even ASCII
characters (if you indeed did that with the comment in *scratch*
copied many times, as your recipe says) is somehow very expensive on
your system.

Does it help to customize inhibit-compacting-font-caches to non-nil?