From: Zack Stackson <zack.stackson@gmail.com>
To: Eli Zaretskii <eliz@gnu.org>
Cc: 15390@debbugs.gnu.org
Subject: bug#15390: 24.3; scrolling in emacs,w32 uses 100% cpu
Date: Wed, 18 Sep 2013 22:53:36 -0500 [thread overview]
Message-ID: <CAE6UpPSJq2QqjmM-t=b-bW-rF5tsd3iJVTb0KOA4OMTYs2enXw@mail.gmail.com> (raw)
In-Reply-To: <838uyxqndb.fsf@gnu.org>
On Mon, Sep 16, 2013 at 1:41 AM, Eli Zaretskii <eliz@gnu.org> wrote:
>
> Mine is 1920x1080 (but I don't think the size matters here, unless you
> are running with the frame maximized, which you didn't say).
I am running with frame height maximized (1440px), performance with
height set to 720px is not nearly as bad.
> > .emacs config:
> > (setq scroll-step 1)
>
> Is that the only thing in your .emacs? I started "emacs -Q", then set
> scroll-step to 1 manually -- do you see the same performance problem
> when you do that? If not, there's something else in your .emacs that
> makes the difference.
I tested with emacs -Q and setting scroll-step to 1 manually, it is the same.
Also tested with emacs -Q and setting font to small size, page up
slowness is the same.
> Emacs 24's display performance is sensitive to the paragraph length as
> well. A paragraph start and end are defined for this purpose as empty
> lines. Is it possible that the text files you used didn't have any
> empty lines at all? If so, can you try files that do have empty
> lines? Also try setting bidi-paragraph-direction to left-to-right
> (it's a per-buffer setting, so use setq-default to do that in all
> buffers).
They did not have any empty lines, adding empty lines made it much faster.
Tried (setq bidi-paragraph-direction 'left-to-right) and (setq-default
bidi-paragraph-direction 'left-to-right), but that did not make it
faster.
> > Result with emacs-24.3 with smaller font (6x10 from X11): scrolls one page,
> > then stops rendering anything (second to last page stays on the screen),
> > uses 100% cpu until top of buffer is reached, then starts rendering again.
> > Result with emacs-22.3 with smaller font (6x10 from X11): scrolling is
> > smooth, renders all pages, 0-50% cpu usage.
>
> Couldn't try this one, since you didn't say which font you used,
> exactly, and how/from where to get it installed on Windows.
Setting font to Consolas size 68 gives similar results to the 6x10
font. (I don't remember which program I used to convert the 6x10 X11
font to windows .fnt)
> Yes, Emacs 24's display is slower than that of Emacs 23, because the
> former supports bidirectional scripts. So it's not a surprise that
> you see some performance degradation. However, that degradation
> should be apparent only in some rare use cases. So the question is,
> what is special in your case?
Emacs 23 is also slow, not as slow as 24, but not much different.
Emacs 22 is very fast, so that's the version I have been using.
Do bitmap raster fonts take more work than other fonts, maybe that's
part of it? The font is 3kb, could I attach it?
Page up is also slow when editing files with syntax highlighting
(replace.el for example).
> Date: Mon, 16 Sep 2013 09:41:52 +0300
> From: Eli Zaretskii <eliz@gnu.org>
> In addition, the characters that begin a paragraph might be of
> importance. You say "text file", so I presume that is human-readable
> text, but it could also be a file with many digits and punctuation
> characters -- these make redisplay work harder.
Yes, there are many numbers and punctuation, just tested with the
following repeated:
AA3036B2-CCCC DD3036E1-FFF Test text Test text Test text Test text Test
But it also happens on syntax highlighted files when using a small font.
next prev parent reply other threads:[~2013-09-19 3:53 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-15 18:41 bug#15390: 24.3; scrolling in emacs,w32 uses 100% cpu Zack Stackson
2013-09-16 6:41 ` Eli Zaretskii
2013-09-16 7:13 ` Eli Zaretskii
2013-09-19 3:53 ` Zack Stackson [this message]
2013-09-19 7:51 ` Eli Zaretskii
2013-09-23 5:32 ` Zack Stackson
2013-09-23 7:07 ` Eli Zaretskii
2019-09-26 12:38 ` Stefan Kangas
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
List information: https://www.gnu.org/software/emacs/
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAE6UpPSJq2QqjmM-t=b-bW-rF5tsd3iJVTb0KOA4OMTYs2enXw@mail.gmail.com' \
--to=zack.stackson@gmail.com \
--cc=15390@debbugs.gnu.org \
--cc=eliz@gnu.org \
/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 public inbox
https://git.savannah.gnu.org/cgit/emacs.git
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).