Hey,

Nope, sorry. Doesn't seem to help.  What I did:
started emacs with

#emacs -Q lorem-ipsum

emacs opens in fundamental mode with the file (attached)

# M-x eval-expression
# (setq inhibit-compacting-font-caches t)
# buffer-face-set
# variable-pitch

Slow as before. Attaching the profiler logs


On 08/04/17 16:44, Eli Zaretskii wrote:
> > From: Gennady Uraltsev <gennady.uraltsev@gmail.com>
> > Date: Sat, 8 Apr 2017 15:48:38 +0200
> >
> > Font rendering in emacs is incredibly slow if any buffer-local change is
> > made i.e. unless using 'default.
>
> Does setting inhibit-compacting-font-caches non-nil solve the problem?
> If it does, can you show an example of a buffer where you see this
> problem?
>