Present: Frank, Eloisa, Erik, Steve, Roland, Peter, Vassili, Ian, Roberto
Failing tests: * boostedpuncture failure likely due to code change * GRHydro tests shows different behaviour depending on options, the test seems to fail only with new enough compiler, and -ffast-math * affected hydro tests are very sensitive to data, it may be sufficient to use a mild increase in resolution * as a general approach we need to decide if we want -ffast-math or if removing it does not affect results too much. It may be sufficient for gcc to specify options that allow the same subset of fast-math that icc uses by default * if fast-math is needed for good performance, then we have to relax test constraints for these tests * action items: ** run production benchmark with and without -fast-math on a modern machine (Erik), use GW150914 ** check if higher resolution helps for hydro tests (Roland)
piraha parser: * Steve has an experimental version that produces multiple syntax errors for ccl files * Ian would be happy with one good syntax error per ccl file and then an abort, Roland would prefer multiple ones. Most importantly multiple errors for par files * if parsing speed is slow (Steve obtained a speedup for parallel parsing in a stand-alone parser but not with the integrated parser). May consider c++ parser with perl fallback if speed is an issue
KNL: * can compile on stampede2, but fail to run with a segfault at startup * Frank managed to compile in an interactive job and run * Roland notes that NERSC's cori has custom modules/code to allow compilation of KNL code on the login nodes, what works on cori does not work for example on a different Cray machine (internal) * wiki for progress https://docs.einsteintoolkit.org/et-docs/Running_Cactus_on_Knights_Landing * Eloisa could obtain similar performance on KNL (~80%) for vacuum simulation as on Broadwel node * CINECA has seminar on KNL, someone from Trento joined and we could try and ask them to give an ET seminar and report back
Yours, Roland