Re: customize-apropos-options takes forever...

[Chong Yidong <cyd@stupidchicken.com>]

"Drew Adams" <drew.adams@oracle.com> writes:

>  M-x customize-apropos-options RET RET
>
> On Emacs 22, this takes quite a while. On Emacs 20, it finishes very
> quickly.
>
> Emacs 22 has a lot more options, of course, and more faces and buttons and
> such, but it still feels like things are less efficient now. In emacs -Q,
> there are 4698 lines in the buffer in Emacs 22; in Emacs 20, there are 2333
> lines (about half). But Emacs 22 takes *far* longer than twice as long.

I took some time to look into this.

For M-x customize-apropos RET RET:

Emacs 22 takes 140.04 seconds to make 1904 entries, i.e. 13.6 / second.
Emacs 21 takes 76.38  seconds to make 1048 entries, i.e. 13.7 / second.

Conclusion: >>>> This Is Not A Bug <<<<

I think the reason you thought Emacs 22 is slower is that the echo
area tells you how much % of the job is done.  Obviously, 1% of 1904
entries takes longer to do than 1% of 1048 entries, giving the
illusion that Emacs 22 is progressing more slowly.

In the reality, of course, it's silly to do M-x customize-apropos with
no regexp in the first place.