I wanted to let others know about my recent experience tuning Org. I'm on Emacs 29.3 with Org 9.7-pre from git.
I have a large file, 5MB, 134k lines, 4k example blocks, 1200 inline images, 6500 timestamps. It grows rapidly as I use it for customer support at a very active customer. I do try to archive completed tasks twice a year to try and get it back under 100k lines. I've had some performance problems with the file as it grows. Recently I was trying to scroll up by just holding page up, and within seconds Emacs would timeout and it could take up to 10 seconds being frozen until it caught up. I asked about this in the recent Org meetup, and I was given great information about how the number of faces used in a file can strongly influence the speed of navigation. I tested in fundamental mode and still had slowdowns, and in emacs -Q it ran normally at full speed. Something was up with faces. I went to bisect my configuration. I don't use many packages, but I dutifully bisected down all my use-packages calls until I had none. The problem still persisted with no add-on packages. I started digging into my configuration, and found that if I disabled global-whitespace-mode the issue vanished. After some searches, it appears that whitespace-mode highlights each space/tab/newline with a face. In a small file that may not matter, but in bulk it was crippling. I changed whitespace-mode to use the display table where it substitutes other characters for spaces instead of using faces, and the performance problem was solved. The following setting made all the difference: (setq whitespace-style '(space-mark tab-mark)) Perhaps I can save someone else some time troubleshooting. ------------------------------------------------------------------ Russell Adams rlad...@adamsinfoserv.com https://www.adamsinfoserv.com/