Is there a way to view the machine name on the Yosemite login screen?
It's been a few versions, I believe, since this was a default.
Open up the terminal.app and run the following command.
sudo defaults write /Library/Preferences/com.apple.loginwindow AdminHostInfo HostName
This will show your computer name, IP, and OS version (build). By default this isn't visible on the login screen until you click on the clock in the top right. Clicking on the clock will toggle through the information.