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slava77 / cmssw

CMS Offline Software
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reduce the number of grid files needed to load MagField #76

Open slava77 opened 9 years ago

slava77 commented 9 years ago

or move fully to DB

slava77 commented 7 years ago

Some notes on the cost:

https://slava77sk.web.cern.ch/slava77sk/reco/cgi-bin/igprof-navigator/CMSSW_8_1_X_2016-05-18-1100-orig-cvmfs.134.905.step3.200.pp/844 shows that for a 200 event job the mag field initialization takes 0.5% of the job magneticfield::VolumeBasedMagneticFieldESProducerFromDB::produce. About a half of this cost is spent to read the input files and parse them.

From earlier tests (at the time of the creation of this issue as of CMSSW_7_4_X_2015-08-14-1100): from 5 min of the jobs startup time 31s is in MagneticField reading