(verb) Military slang for goodbye, or I'm leaving.
This term draws it's meaning from soldiers literally popping smoke grenades to mark an extraction zone. Which is done at the conclusion of a mission, immediately before the soldiers leave that operating area.
Dave: Hey buddy you enjoying my party?
Matt: Nah man, this place is a total sausage fest, I'm poppin smoke.
Dave: Alright, see you later.