Subject: bug#26402: 25.2; Font rendering extremely slow on any non-default font

From: Eli Zaretskii <[email-masked]>
Date: Sat, 08 Apr 2017 17:44:48 +0300

> From: Gennady Uraltsev <[email-masked]>
> 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?