package-menu-mark-upgrades
package-menu-mark-upgrades is an interactive compiled Lisp function in `package.el
'.
(package-menu-mark-upgrades)
Mark all upgradable packages in the Package Menu.
For each installed package with a newer version available, place
an (I)nstall flag on the available version and a (D)elete flag on
the installed version. A subsequent M-x package-menu-execute
call will upgrade the package.