GNU bug report logs - #13675
24.2.93; Extremely slow redisplay when lines are very long

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Package: emacs;

Reported by: Eli Zaretskii <eliz <at> gnu.org>

Date: Sun, 10 Feb 2013 16:27:01 UTC

Severity: normal

Merged with 3219, 4123, 9589, 15555, 18530, 22143, 24523, 30457, 32523, 40007

Found in versions 23.1, 24.2, 24.2.93, 24.3, 24.5, 26.0.91, 27.0.50, 28.0.50

Fixed in version 29.1

Done: Lars Ingebrigtsen <larsi <at> gnus.org>

Bug is archived. No further changes may be made.

Full log


Message #8 received at 13675 <at> debbugs.gnu.org (full text, mbox):

From: Eli Zaretskii <eliz <at> gnu.org>
To: Eli Zaretskii <eliz <at> gnu.org>
Cc: 13675 <at> debbugs.gnu.org
Subject: Re: bug#13675: 24.2.93;
	Extremely slow redisplay when lines are very long
Date: Sun, 10 Feb 2013 19:36:30 +0200
> Date: Sun, 10 Feb 2013 18:26:14 +0200
> From: Eli Zaretskii <eliz <at> gnu.org>
> 
> This is a very long-standing deficiency of the Emacs display engine:
> it is awfully slow in buffers with very long (thousands of characters)
> lines.  Specifically, many simple movement commands, scrolling, or
> even typing "M-x" can take several seconds(!) to complete.
> 
> A simple Awk script attached below can be used to generate such files.
> 
> For the latest discussions of this and some data, see this thread:
> 
>   http://lists.gnu.org/archive/html/emacs-devel/2013-02/msg00135.html
> 
> The solution for this bug should produce algorithmic changes in the
> display engine and possibly also supporting changes in data structures
> that would prevent such a terrible slow-down with long lines.
> Ideally, redisplay of such buffers should not be much slower than
> buffers with "normal" line length.

Revision 111724 speeds up some of the redisplay operations by a factor
of 3.




This bug report was last modified 2 years and 300 days ago.

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