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

[Oleksandr Gavenko <gavenkoa@gmail.com>]

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!