Hi Noam,

Thanks for the tips. One (package-earlyload) is to put package-initialize before custom-set-variables, another one (package-lateload) is to put package-initialize after then custom-set-variables. I attahed the diff of the trace-log.

The trace-log from package-earlyload has less do-after-load-evaluation items which are supposed to be loaded during the package-initialize. However, it still takes longer time for custom-set-variables during early package initialization.

The two items, mail-prsvr.elc and mm-util.elc are in earlyload but not in lateload.

On Tue, Mar 13, 2018 at 1:09 AM, Noam Postavsky <npostavs@gmail.com> wrote:

On Mon, Mar 12, 2018 at 12:08 PM, Shuguang Sun <shuguang@gmail.com> wrote:
> FYI. If put (package-initialize) before custom-set-variables,
>>>> before custom-set-variables : 3.637 sec <<<
> Loading image-file...done
> Loading time...done
> Loading completion...done
> Loading elec-pair...done
> Loading icomplete...done
> Loading ido...done
> Loading avoid...done
> Loading savehist...done
> Loading paren...done
>>>> custom-set-variables time: 10.080 sec <<<
>
> Don't know whether autoloads being triggered. It is hard to test one by one.

Try

...
(require 'trace)
(trace-function 'do-after-load-evaluation)
(custom-set-variables ...)
(untrace-function 'do-after-load-evaluation)

and see if there is a difference in the *trace-output* buffer when you
call package-initialize first.

Maybe also do (mapc #'require '(image-file time completion elec-pair
ido avoid savehist paren)) to get the known loads (which I see listed
in your output above) out of the way.