[O] Re: org-src-fontify-natively makes things very, very slow

[Ulf Stegemann]

Hi Sébastien, Eric,

I'm experiencing the same performance problems with recent org-mode.  My
observations are ...

Sébastien Vauban <address@hidden> wrote:

> Eric S Fraga wrote:
>>
>> From these timings, the font locking doesn't seem to be the issue but maybe
>> the overlays are. However, commenting out the code that Sébastien Vauban
>> indicated:
>>
>>> Maybe this is (partly?) due to the overlay I added:
>>>
>>> #+begin_src emacs-lisp
>>>                 (overlay-put (make-overlay beg1 block-end)
>>>                              'face 'org-block-background))
>>> #+end_src
>
> See http://patchwork.newartisans.com/patch/581/ for a full diff. You can see I
> only add *one* overlay: for the background face.
>
>> (well, commenting out the whole condition that includes this code) makes no
>> difference at all.

That's true. It does not make any difference performance-wise.

>> So, I turned off =org-src-fontify-natively= and things are back to
>> normal: next-line is as fast as previous-line.  I can put up without the
>> fontification so this is what I am doing now.

It's true that setting `org-src-fontify-natively' to nil boosts
performance but it's only half the story.  Editing something inside
blocks also has a significant negative influence on display performance.
Removing things like `#+BEGIN_letter' / `#+END_letter' from the file
gets things back to normal for me.

Ulf