org-mode using 100 CPU, weird note, or just too many of them?

[Gijs Hillenius <gijs@hillenius.net>]

I almost daily, and most certainly weekly, store notes in org-mode. Bin
doin' that since somewhere in 2007. The file is now a measly 184k.

Org-mode's weekly task list works fine. And storing notes works fine
too. However, actually using these notes, is not.

Every time I even "look" at the file, CPU utilisation jumps to 101
percent (two cores), according to 'Top'. It takes a while too, before it
settles down.

I can search (C-a s) fine, but when jumping to the resulting note, this
will lock emacs for a while. And opening the note (tab) will lock it up
again.

I wonder, did I store some note that does something weird, like asking
Org-Mode to calculate something from day 0 (4.54 billion years ago) to
'Judgement Day'?

So, yesterday I decided to cut the file in parts. I threw aside all the
notes stored before 2010. Made no difference. I threw aside all the
notes that were made before 2011. That helped, now emacs' CPU
utilisations is not above 50 percent and it is ok like that.

So maybe the error is in a note from 2010? However, stripping all 2010
notes, the CPU is blocked once more.. so maybe it is not the 2010 notes?

I'm not sure how to debug this. I've switched on the debugger, and tried
hitting C-g when the CPU is at 100%, but the debugger comes up empty.

Now what? Should I simply move all notes to the archive? That is fine
with me, if search still works. But I bet then I simply will have moved
the problem *there*?