How can I speed up Emacs DocView mode?

Question

I'm using a fairly standard install:

• Ubuntu 12.04 LTS (installed less than a week ago)
• GNU Emacs 24.1

And when I open a PDF file in Emacs, it's terribly slow. There's a 2-3 second delay when simply scrolling with the mouse, 1-2 second delay when using n, p, C-p, C-n, etc.

This is with a 20-page doc. With a 50-page doc like this one, Emacs becomes unusable (constant freezing), so the problem gets worse with document size.

How would I go about fixing this?

Answer 1

When I ran emacs -Q, the problem went a way. I isolated it to this line in my .emacs.d/init.el file:

(global-linum-mode 1)

If I comment that out and restart Emacs, I can scroll on PDFs and I get no UI delay whatsoever. If I turn it back on with M-x global-linum-mode, the long lag between mouse scroll and UI update comes back.

Answer 2

To disable linum-mode when you are in DocView mode, you can use the following setup file: setup-linum.el You can customize by editing line number 5