bug#17837: 24.4.50; Search very slow

[Eli Zaretskii]

> Date: Mon, 23 Jun 2014 21:08:59 -0400
> From: Richard Stallman <rms@gnu.org>
> CC: monnier@iro.umontreal.ca, 17837@debbugs.gnu.org
> 
> C-s honor  [to set the search default]
> C-x b 2014-mar-jun.html RET
> M-<
> C-s C-s
> [wait to find the first occurrence]
> C-s [search for the second occurrence]
> 
> I counted around 45 seconds before it found the second occurrence.

For me, the first one is slower: about 5 to 6 sec.  The second
occurrence takes maybe 3.  Stefan, what's your timing?

> In Emacs 23.2, the second occurrence takes only 7 seconds.

Yes, I see some slowdown wrt 23.2, although not as drastic.  Are you
sure both binaries were compiled similarly, e.g. as far as compiler
optimization switches are concerned?

Anyway, you may wish to experiment with setting jit-lock-defer-time to
a non-nil value.  E.g., try setting it to 0.25 or 0.5 sec, and see if
that gives good results.