From: Eli Zaretskii <eliz@gnu.org>
To: Kai Ma <justksqsf@gmail.com>
Cc: luangruo@yahoo.com, gerd.moellmann@gmail.com, alan@idiocy.org,
71454@debbugs.gnu.org
Subject: bug#71454: 30.0.50; Performance issues with font selection
Date: Fri, 27 Sep 2024 13:29:13 +0300 [thread overview]
Message-ID: <86o7498k5i.fsf@gnu.org> (raw)
In-Reply-To: <88D40848-CC43-4397-81EA-4BBB4B2EAC30@gmail.com> (message from Kai Ma on Fri, 27 Sep 2024 09:51:06 +0200)
> From: Kai Ma <justksqsf@gmail.com>
> Date: Fri, 27 Sep 2024 09:51:06 +0200
> Cc: Alan Third <alan@idiocy.org>,
> Po Lu <luangruo@yahoo.com>,
> Gerd Möllmann <gerd.moellmann@gmail.com>,
> 71454@debbugs.gnu.org
>
> This part, about _any_ unusual characters causing a significant delay,
> seems to imply that the default fontset is not set up correctly on
> your system (or maybe in general on macOS), or perhaps that the way
> the fontsets are used on macOS is very different from other systems.
> For starters, are the fonts that Emacs selects for the characters you
> used for testing different from the fonts defined by fontset-default
> for those characters? If so, what happens if you modify
> fontset-default (using set-fontset-font) to specify for these
> characters the same fonts as what Emacs selects with the default value
> of fontset-default? does font selection become much faster (it
> should)?
>
> Yes, if I manually set the font, it becomes instant.
Thanks, so it means finding a font that matches the default font's
spec is indeed slow on your system.
I wonder if this is a general issue with macOS, or just with the
version and/or configuration you are running.
> It could also be the matter of selecting the default face's font. For
> best results, it should be a font that covers many popular scripts, at
> the very least Latin, Cyrillic, and Greek. Judging by the "unusual"
> characters you show, it sounds like Latin characters are not well
> covered by your default face's font? If so, perhaps choosing a font
> with better coverage will make the situation better for you?
>
> It would not eliminate the problem though.
I didn't mean that it will. However, being able to display more
characters without delays is a Good Thing regardless.
> Based on the profiling, my guess is that CTFontDescriptorCreateMatchingFontDescriptors is doing a linear
> search internally (it probably didn’t just pick the specified by the font family?), so macfont_list is accidentally O
> (n^2). This (if true) should explain why it’s so slow.
Yes, you said that in your original report.
next prev parent reply other threads:[~2024-09-27 10:29 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-06-09 18:56 bug#71454: 30.0.50; Performance issues with font selection Kai Ma
2024-06-09 22:10 ` Jeremy Bryant via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-06-09 22:17 ` Kai Ma
2024-06-09 22:34 ` Jeremy Bryant via Bug reports for GNU Emacs, the Swiss army knife of text editors
2024-06-10 2:14 ` Kai Ma
2024-06-10 12:04 ` Eli Zaretskii
2024-06-09 23:10 ` Jim Porter
2024-06-10 2:18 ` Kai Ma
2024-06-10 11:53 ` Eli Zaretskii
2024-06-10 16:31 ` Jim Porter
2024-06-10 17:35 ` Eli Zaretskii
2024-06-10 11:55 ` Eli Zaretskii
2024-06-10 12:35 ` Kai Ma
2024-06-10 12:59 ` Eli Zaretskii
2024-06-10 16:42 ` Gerd Möllmann
2024-06-10 17:36 ` Kai Ma
2024-06-10 18:05 ` Gerd Möllmann
2024-06-10 11:58 ` Eli Zaretskii
2024-06-10 12:34 ` Kai Ma
2024-06-10 13:03 ` Eli Zaretskii
[not found] ` <22612F93-FC37-48E8-8137-E9FF6F5B3A0D@gmail.com>
2024-09-27 6:32 ` Eli Zaretskii
2024-09-27 7:51 ` Kai Ma
2024-09-27 10:29 ` Eli Zaretskii [this message]
2024-09-28 3:36 ` Gerd Möllmann
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=86o7498k5i.fsf@gnu.org \
--to=eliz@gnu.org \
--cc=71454@debbugs.gnu.org \
--cc=alan@idiocy.org \
--cc=gerd.moellmann@gmail.com \
--cc=justksqsf@gmail.com \
--cc=luangruo@yahoo.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
Code repositories for project(s) associated with this external index
https://git.savannah.gnu.org/cgit/emacs.git
https://git.savannah.gnu.org/cgit/emacs/org-mode.git
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.