To improve batch processing performance, in the History panel,select History Options from the fly-out menu and deselect Automatically Create First Snapshot. Depending on the length of your action, you might also want to reduce the number History States in the Preferences > Performance panel. Just don't forget to increase the number of states when you finished batch processing!
Most people only think of the History panel for multiple undo - but it does much more! Check out the options available through the History panel’s fly out (in the upper right) such as if and when to take Snapshots and Non-Linear History (to retain more current history states if you go back in History and want to try other options without loosing the more current states).
And this is a good time to add that if you do choose to Automatically Create First Snapshot (which is Photoshop’s default setting), you can “undo” an accidental save by clicking on the initial snapshot in the History panel, saving the file, and then returning to your current state and choosing to “Save As”.