Emacs tooooo slow on loooooong line (eat my 2 GHz CPU).

[Oleksandr Gavenko]

I experiment ever with:

  $ emacs --no-init-file --no-site-file

GNU Emacs 23.2.1 (i686-pc-cygwin) of 2010-05-08 on laptop
GNU Emacs 23.2.1 (i386-mingw-nt5.1.2600) of 2010-05-08 on G41R2F1


When single line is more then 10 KiB long Emacs freeze.

For example try typing (1000 times repeat simple text):

C-SPC int main() {return 0;} SPC M-w C-x ( C-y C-x ) C-u 1 0 0 0 C-x e

After text appear in buffer try move up/down by this text.
My CPU loading up to 100%.

Cygwin Emacs in mintty work near 2x time faster
then Emacs native in gui.


Currently I found longline-mode. With such settings:

(setq longlines-show-hard-newlines t)
(longlines-mode 1)

it is speedy but not so visual convenient
as default line wrapping mechanism.


Also I try visual-line-mode. It also very slow!


I try Emacs 21.3 and found that there no such feature as
moving to wrapped part of line by one line. Instead if I
press UP or DOWN in go to new line. And very fast!
Same with Emacs 22.3.

How back previous behavior on long line moving or fix
current?

--
Best regards!