Package: emacs;
Reported by: <gennady.uraltsev <at> gmail.com>
Date: Thu, 2 Apr 2020 00:07:02 UTC
Severity: normal
Tags: moreinfo
Found in version 26.3
Done: Lars Ingebrigtsen <larsi <at> gnus.org>
Bug is archived. No further changes may be made.
View this message in rfc822 format
From: <gennady.uraltsev <at> gmail.com> To: "'Eli Zaretskii'" <eliz <at> gnu.org> Cc: 40384 <at> debbugs.gnu.org Subject: bug#40384: 26.3; [Windows10] variable-pitch-mode is slow to redraw 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)
as given by describe-char. On the other hand I can, before enabling the
mode, execute
(custom-set-faces
'(variable-pitch ((t (:height 120 :family "Segoe UI" :foundry "MS " :slant
normal :weight normal :width normal)))))
and this gives
display: by this font (glyph code)
uniscribe:-outline-Segoe UI-normal-normal-normal-sans-24-*-*-*-p-*-iso8859-1
(#x37)
But slowness happens in both cases.
Here are the profiler reports for CPU for scrolling about 2 pages worth of
text by pushing the down arrow:
******Normal*******
- command-execute 3 75%
- call-interactively 3 75%
- byte-code 3 75%
- read-extended-command 3 75%
- completing-read 3 75%
- completing-read-default 3 75%
read-from-minibuffer 2 50%
- ... 1 25%
Automatic GC 1 25%
******variable-pitch-mode*******
- command-execute 92 97%
- call-interactively 92 97%
- funcall-interactively 91 96%
- next-line 89 94%
- line-move 89 94%
- line-move-partial 59 62%
- default-line-height 36 38%
default-font-height 36 38%
- window-screen-lines 23 24%
- default-line-height 23 24%
default-font-height 23 24%
- default-line-height 30 31%
default-font-height 30 31%
- execute-extended-command 2 2%
- sit-for 2 2%
redisplay 2 2%
- byte-code 1 1%
- read-extended-command 1 1%
- completing-read 1 1%
- completing-read-default 1 1%
- read-from-minibuffer 1 1%
- redisplay_internal (C function) 1 1%
- tool-bar-make-keymap 1 1%
- tool-bar-make-keymap-1 1 1%
- mapcar 1 1%
- #<compiled 0x1000d70c9> 1 1%
- eval 1 1%
- find-image 1 1%
image-search-load-path 1 1%
- ... 2 2%
Automatic GC 2 2%
Thanks!
-----Original Message-----
From: Eli Zaretskii <eliz <at> gnu.org>
Sent: Thursday, 2 April, 2020 10:41
To: gennady.uraltsev <at> gmail.com
Cc: 40384 <at> debbugs.gnu.org
Subject: Re: bug#40384: 26.3; [Windows10] variable-pitch-mode is slow to
redraw
> From: <gennady.uraltsev <at> gmail.com>
> Date: Wed, 1 Apr 2020 20:06:38 -0400
>
> I am trying to emacs under Windows 10. variable-pitch-mode is insanely
> slow in redrawing the screen. With a clean emacs.d I opened a text
> file and tried pressing the down arrow. The cursor gets redisplayed
> every 10 lines or so and emacs is very sluggish. It is interesting
> that this DOES NOT happen with a normal, fixed-pitch, font and also
> does NOT happen if I set the default font to be a variable pitch one
> e.g. "Segoe UI". It only happens with variable-pitch-mode.
I don't think I can reproduce this.
Which font is used on your system when you turn on variable-pitch-mode?
(You can type "C-u C-x =" on a character to see the font used to display
it.)
> Attached are profiler results for moving down two pages worth of text.
Thanks, but you provided a "memory" profile, which is almost useless.
Please provide the "cpu" profile instead, and please show it in
human-readable form (after performing the measurement, type "M-x
profiler-report RET", then go to each top-level "+" sign and type "C-u RET"
to expand the profile; and finally paste the result into your message and
send it).
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