I never use commas because they slow down the reader. You don't need anything but periods if you are writing well and you don't even need those if you don't want to use them. A friend read one of my stories. Why don't you use any punctuation? she asked me. I told her I was trying to create a sense of immediacy. Starkness. No longer any boundaries between reader and narrator.
Or maybe I'd just been reading too much Cormack McCarthy.