Auto-revert/notify behavior changed?

[Yuri D'Elia <wavexx@thregr.org>]

I'm using auto-revert-mode for a few specific files (the mode is enabled
via dir-locals.el).

A few months ago the files were reverted pretty much instantaneously
when changes occurred on disk, as expected.

This doesn't seem to be the case in the current master anymore despite
me not changing or seeing anything related in the latest changes in
autorevert.el.

Setting a shorter auto-revert-interval seems to work, which (I guess)
notifications are not working as expected, despite these buffers being
associated to boring regular files.

I double-checked my config, and emacs is always built with notification
support (inotify).

I'm not sure where to start looking...