Re: Slow/poor responsiveness in org files

[Mathieu Boespflug]

Eli Zaretskii <eliz <at> gnu.org> writes:

> 
> > Date: Mon, 22 Aug 2011 10:52:49 +1000
> > From: Tim Cross <theophilusx <at> gmail.com>
> > Cc: emacs-devel <at> gnu.org
> > 
> > SOLVED!
> > 
> > Adding the line
> > 
> > (setq bidi-display-reordering nil)
> > 
> > to my org-mode-hook has fixed the problem. Cursor movement and editing
> > operations are now usable and the delays are gone.
> 
> Please don't consider this a solution.  bidi-display-reordering should
> not slow down redisplay to a degree that makes Emacs unusable.  And
> setting bidi-display-reordering to nil means that R2L scripts cannot
> be used in Org buffers, which is clearly unacceptable.

I have experienced precisely the same behaviour in some of my org files. Here is
a link to a large (redacted) org file that exhibits this problem:

http://www.cs.mcgill.ca/~mboes/test.org

With latest emacs 24, reading this file in org-mode is noticeably slower than in
org-mode, even when all trees are folded. However that's behaviour I don't see
with emacs -Q. What I do see even with emacs -Q is very slow cursor movement and
editing after expanding the tree titled "LONG". You have to scroll down to near
the end of that tree to see what I'm talking about. Navigating subsequent trees
when the LONG tree is expanded is also slow.

>  . Does the slowdown go away after "M-x show-all RET"?

The slowdown does indeed completely disappear appear this command.

>  . Does setting bidi-paragraph-direction to `left-to-right' eliminate
>    the slowdown?

Yes.

-- Mathieu