The speed of Emacs 21

[John Wiegley]

Sometime in the last two weeks, it appears that e21's Lisp interpretor
(or something) has slowed down dramatically.  Here are some places
where it's really noticeable:

  Type `G c' in the Gnus *Group* buffer, to customize a group's
  parameters.  This takes 10 seconds on my 700 MHz machine, with
  nothing else running!

  Type `ls -l' in a large directory in Eshell.  This takes WAY longer
  than it ever used to, and consumes tens of thousands of cons cells.
  In fact, it often causes e21 to dump core (I haven't debugged this
  yet).

Anybody have any ideas on how I can begin to track this down?  Anyone
remember recent changes that would lead to this kind of slow-down?