From: Konstantin Kharlamov <hi-angel@yandex.ru>
Date: Mon, 11 Mar 2019 00:19:45 +0300
Result of (benchmark-run-compiled …) has suspiciously unevenly
distributed numbers. E.g. it might give all 100% to garbage
collector,
as if no other code was ran. This was found as part of thread about
slow
lexical-binding, and I was asked to report it.¹
1:
http://lists.gnu.org/archive/html/help-gnu-emacs/2019-03/msg00056.html
# Steps to reproduce (in terms of terminal commands):
1. wget
https://gitlab.freedesktop.org/libinput/libinput/raw/9a2d6f55b1276da11dd9b2c4c8e22a405576dfea/src/libinput.h
2. emacs -Q --eval "(progn (find-file \"./libinput.h\")
(profiler-start 'cpu) (benchmark-run-compiled 10
(c-font-lock-fontify-region 0 (point-max))) (profiler-report))"
## Expected:
Some of percentages should be inside cc-mode code.
## Actual:
- ... 1 100%
Automatic GC 1 100%
Not reproducible on my system (I get a reasonable profile, with over
100 lines, which points to font-lock-fontify-keywords-region and
c-find-decl-spots as two likely bottlenecks).
So I think Glenn is right, and this has something to do with your
kernel.