Hi

Present were: Bhavesh, Elo, Erik, Frank, Gwyneth, Ian H., Peter, Roberto, 
Steven, and Vassili

Status on KNLs
Some independently developed optionlists exist, but none are production-ready:
- Erik's optionlist on Cori: in branch in simfactory2
- Frank will put his option list into simfactory.
- Eloisa has one for Marconi + KNL, and will also put it in simfactory.

Test suites and Jenkins:
- Erik: optimizations on "jenkins" use optimization, performance difference ~8%
  - discussion about
   - whether to use optimizations or not / whether 8% are ok to loose
   - whether optimizations "dangerous" or not.
  - result for now: try to see if testsuites are broken and fix, if possible.
- Eloisa will look at boostedpuncture test case
- Roland will look at Spec test suites
- Frank &| Roland will have a look at the hydro failure

Piraha CST parsing (Stev):
- caching parse-tree cuts down time practically to 0
- files holding cache (one per ccl file) will be within configurations
- plan: new ticket, branch, eventually inclusion
- parallelism problematic with Perl, but may not be needed anyway

Gwyneth asked:
- Constraints: what/how to use to calculate?
- ML_AMD_Contstraints: uses ADM constraints, independent of evolution system
  - McLachlan: uses BSSN variables, no need to calculate ADM variables
  result: It does (and should) not really matter.
    Preferences for one or the other exist, and may depend on
    particular simulation specifics, but both should get the results
    to within numerical accuracy.
- What thorn to use for which output type (basic/scalar/ascii)
  (Frank: It would probably be good to have this as overview on a page or so.)
- Question about comment in bbh gallery example par file:
  "SummationByParts::sbp_upwind_deriv": not required for that parameter file
    would drop order of derivatives near boundary in some cases, but
    derivatives are not used here
- ADMMass: how to measure
  - using initial data output (but that might differ from the one on the finite 
comp. grid)
  - ADMMass thorn: surface integral    or
  - ADMMass thorn: volume integral (but needs thorn not in the toolkit to 
excise BHs) or
  - QuasiLocalMeasures: surface integral
- time refinement factors on coarse grids
  - Stricter requirements on time step on very coarse grids than regular cfl 
factor may
    lead to instabilities (gauge evolution in particular).
  - Result: don't need to use if no instability seen.

Frank

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