by Jesper van Engelen on WordPress.org
Adds an option to the admin posts and terms overview pages to select all items (instead of just the ones on the current page) to apply bulk actions.

When clicking on the "Select all" checkbox in the top left of your posts/terms table, a notice appears to select all posts/terms
Bulk Actions: Select All adds an option to the posts and taxonomy terms overviews in the WordPress Admin to select “All Entries”. By default, WordPress only allows you to select the posts/terms on the current page.
The plugin works for posts, pages and custom post types. Furthermore, it supports categories, tags and custom taxonomies. At this point, it doesn’t support comments and other object types besides post types and taxonomies.