Meeting Date: 4/3/2017
Attendees: D. Abdurachmanov, M. Alef, L. Atzori, B. Bockelman, J. Flix, A. Forti, D. Giordano, C. Grigoras, D. Lange, A. McNab, M. Michelotto, A. Perez-Calero, M. Reis, A. Sciaba, L. Sexton-Kennedy
1) News (Domenico)
- Question about branch prediction effect on the python switch case of DB12: what would be the effect of a C++ implementation of DB12?
- Why DB12 is implemented in python?
- Andrew: because it came out from experimental evidence that it scales with the LHCb MC applications
2) CMS report (Pepe)
- Running ttbar MC events
- known that there is an overhead of initializations and that also the last event takes long.
- those are irreducible parts that motivate the choice of running on a large number of events
- Large fluctuations of DB12 when running in the region of HT=ON
- Comments: it's related to the adjustment of the CPU frequency. It would be useful to fix the CPU frequency or at least monitor it
- Ratio plot: it would be better to normalise to the number of processes== number of physical cores, and not to 1, to better compare the performance of HS06, DB12 and ttbar in the HT region. Indeed it seems that HD06 and ttbar are correlated in that region.
- Andrea S. comment: CPU model is not available in CMS pilots
- Answer: it will be added, work ongoing
- Pepe: to document how to run cmssw application and simulate ttbar events
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