Subject: Re: bug#9610: 24.0.90; org-mode: sluggish response and high CPU utilization with large .org files

From: Steve Revilak <[email-masked]>
Date: Tue, 27 Sep 2011 19:47:39 -0400

>> My bug report contained two scenarios to produce sluggish response and
>> high CPU utilization.  These scenarios were
>>
>>   (1) move point to the end of buffer, and start typing
>>
>>   (2) Put point in line 1, column zero; press and hold the down (then up)
>>   arrows to move point down (then up) the org-mode buffer.

>Yes, there was another reason for the slowdown.  I found an
>optimization of the new display that solves the problem for me with
>your sample Org file.  The fix is committed as revision 105941 on the
>trunk.  If you cannot or don't want to build the trunk, the patch is
>reproduced below; please try it.  On my machine, the cursor motion is
>now as fast as in Emacs 23 with the same file.

Eli,

I've tried your src/xdisp.c patch.  It completely fixes scenarios (1)
and (2), without the need to set bidi-paragraph-direction.

I've tested the patch on two different systems: GNU/Linux (OpenSUSE
11.4) and Mac OS 10.6.  Same (good) results on both.

Thanks so much for the quick response!

Steve

(I've mailed this to [email-masked]; my intent was to
provide confirmation of the fix, but to leave bug 9610 closed.)