buffers-menu-max-sizebuffers-menu-max-size is a variable defined in `
menu-bar.el'. Its value is
10Documentation: Maximum number of entries which may appear on the Buffers menu. If this is 10, then only the ten most-recently-selected buffers are shown. If this is nil, then all buffers are shown. A large number or nil slows down menu responsiveness. You can customize this variable.