The map module will automatically geocode newly created or imported locations using Geocoder as long as they contain an address. When creating a single map location, the geocoding is fairly instantaneous. When dealing with a large number of locations simultaneously, the geocoder may hit rate limits, in which case it will continue geocoding as long as the node process continues to run.
If you are running in a multiple-process environment, like cluster, you should set the startGeocoder option to false and explicitly invoke the startGeocoder method from one and only one process to avoid hitting API rate limits.