cms-sw/cmssw — pull request #5106 by davidlange6 (2014-08-29 11:05:45+00:00)
Title: hash function for pileup summary info

All that is available without tracking particles is the # of pileup vertices per bx. At 40 PU and with 16bx, this is plenty of information to make a reliable hash to use to check for duplicates in RECO samples where premixing was used.