auto-revert in VCS

[Andrea Crotti]

I would like to have auto-revert activated when I work with branches.
For example in git projects every time I change branch I have to revert
buffer manually to start working on the new branch.
So I wrote this in my conf:

--8<---------------cut here---------------start------------->8---
(require 'autorevert)
(setq auto-revert-check-vc-info t)
(setq auto-revert-interval 3) ;; this could be cpu consuming
(setq auto-revert-verbose t)

(setq global-auto-revert-mode t)
--8<---------------cut here---------------end--------------->8---

The problem is that emacs was sucking all my cpu power and that's not
nice...
I only need to enable auto-revert for files under revision control, and
only on files which I'm visiting in some buffers (and the buffer is
active), is that possible somehow?