Barry Smith <bsm...@petsc.dev> writes: >> What is the command line option to turn >> PetscLogGpuTimeBegin/PetscLogGpuTimeEnd into a no-op even when -log_view is >> on? I know it'll mess up attribution, but it'll still tell us how long the >> solve took. > > We don't have an API for this yet. It is slightly tricky because turning it > off will also break the regular -log_view for some stuff like VecAXPY(); > anything that doesn't have a needed synchronization with the CPU.)
Of course it will misattribute time, but the high-level (like KSPSolve) is still useful. We need an option for this so we can still have -log_view output. Note that Mark's logs have been switching back and forth between -use_gpu_aware_mpi and changing number of ranks -- we won't have that information if we do manual timing hacks. This is going to be a routine thing we'll need on the mailing list and we need the provenance to go with it.