How to make my customized emacs load faster?

Question

As I add more and more plugins and configurations to my emacs' init.el , it's startup is getting more and more slow. Is there any way to avoid this?

Holophytic

possible duplicate of How can I make Emacs start-up faster? – Crosswind

Answer 1

Your .emacs or init.el shouldn't have many require or load commands, it should mostly have autoload. The autoload function tells Emacs “if you ever need this function, load that file”. This way, the file is only loaded when and if you actually use the function. You only need require (or very rarely load) in two cases:

• if there's a customization that needs to go into effect immediately (e.g. (require 'cl), a color theme);
• if what you're loading is a small file that contains the autoloads and other start-up definitions of a package (e.g. (require 'tex-site).

If you're not doing this already, calling autoload for things like mode-specific customizations can cut your startup time down significantly, because Emacs will have to load fewer files.

Furthermore, make sure your files are byte-compiled; they'll load a little faster (less CPU time). Call M-x emacs-lisp-byte-compile on each .el file, or M-x byte-recompile-directory (these commands are in the Emacs-Lisp menu).

Finally, note that load times don't matter so much because you should be starting Emacs at most once per session. Start Emacs automatically when you log in, either with a window or in the background with the --daemon option. Then, to edit a file, run emacsclient. You can also tell emacsclient to start Emacs if it's not running yet if you'd rather not start it when you log in.

Septuagenarian

For people having problems with the daemon mode and the editor colors, this is very useful: emacswiki.org/emacs/SettingFrameColorsForEmacsClient – Rigby

If you don't like confirming every directory and/or file: (byte-recompile-directory "~/where-i-put-my-packages/" nil nil) or change the last nil value to something non-nil to force recompilation. (describe-function 'byte-recompile-directory) rocks :) – Glomerulus

Answer 2

You can compile it as an .elc file (M-x byte-compile-file)

Bul

From 48.4 The Emacs Initialization File: "Byte-compiling your init file is not recommended ... If your init file defines many functions, consider moving them to a separate (byte-compiled) file that you load in your init file." – Uncovered

...That said, there are suggested mechanisms for automatically maintaining a byte-compiled version of your Emacs initialization file. For instance, see here and here. – Uncovered