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

[Oleksandr Gavenko]

On 2010-08-16 1:29, Deniz Dogan wrote:
> 2010/8/15 Oleksandr Gavenko<gavenkoa@gmail.com>:
> > 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?
Back to previous behavior done by:

  (setq line-move-visual nil)

> For what it's worth the sluggishness is a known issue and was reported
> the first time a while back:
> http://debbugs.gnu.org/cgi/bugreport.cgi?bug=3219
Thanks for pointing.

Also I found useful related links in

http://xahlee.org/emacs/emacs_line_move_visual.html


Note that cursor movement at the end on very long line
eat many CPU cycles. At the beginning lesser.

--
Best regards!