Re: Speeding up Emacs load time

[Sebastien Vauban]

Hi Glyn and all,

Glyn Millington wrote:
> One popular technique is not to load packages until you need 'em. That means
> fewer 'requires' in your .emacs/init.el file and more autoloads.
>
> See tips 3-5 here!
>
> http://a-nickels-worth.blogspot.co.uk/2007/11/effective-emacs.html
>
> The key function is eval-after-load

I'm using GNU Emacs on Windows, and using the above, I could reduce my load
time from 10+ seconds to 3 seconds. Still 3 x over many of you, which report
sub-seconds load time.

Though, I'm a bit blocked. I don't understand how to do better, or how to
completely avoid all the require commands.

Just take a few exemple:

- `(server-start)' takes more than 200 ms to run [1]; just that one command.
  Though, I must have it in my .emacs file, right?

- diff-mode-.el must be loaded before diff-mode; hence, I must have it at
  startup.

- Helm is my tool for opening files or switching between buffers. Just
  requiring `helm-config' (almost only autoloads) -- hence, NOT `helm' (which
  is more hungry in time) -- already takes 160 ms (as it still requires
  `easy-menu' and `helm-aliases').

- `diary-lib' and co (needed for appointments notification) takes 233 ms.
  Shouldn't I be notified at startup of events occurring in less than 15
  minutes, without having to make a first call to calendar or so?

- `mic-paren' takes just 32 ms, but for just one small package, for which I
  don't have a particular trigger. Is it `find-file-hook'?  Then, I won't have
  parenthesis highlighted when directly typing text in a newly created buffer
  (or in the scratch). So, I need it in my .emacs. It's not eval'ed-after-load
  of something else.

- The same for YASnippet (loaded in 130 ms): what would be the trigger?
  Unless I have a clear one, I must require it in my .emacs file.

- Once again, the same with `recentf', which takes 92 ms. Don't I have to load
  it right at startup?

These are a couple of examples which take a lot of the time, and for which I
don't see a specific trigger that would allow me to defer their load to later.

Any comments?

Best regards,
  Seb

[1] The above are times on a very recent laptop i7, when on mains. Multiply
    times by 3.5 when on battery.

-- 
Sebastien Vauban