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

[Deniz Dogan]

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?
>
> --
> Best regards!
>
>
>

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

-- 
Deniz Dogan