Kanev[1] disagrees. Flat profiles are the common case in actual practice.
Edited to add: Since apparently you also work at Google, you should walk over to Svilen's desk and just ask him if profiles of production software are generally flat, or if they generally have hot spots.
Edited to add: Since apparently you also work at Google, you should walk over to Svilen's desk and just ask him if profiles of production software are generally flat, or if they generally have hot spots.
1: https://static.googleusercontent.com/media/research.google.c...