Best approach to update all entries in a list that is paginated?

I have a list which is paginated in a webpage. It also has a function to select the number of entries per page. A bulk update on all is required.

What would be the best approach to this? My concern is that a user would doubt if we refer to the current page or to the whole list. A confirmation window with details or an info message to detail it would suffice?

This is how it looks for now: