Fix: GPU runs w/o GPU-Aware MPI#1532
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A few of our reductions in collective effects where assuming we have GPU-aware MPI support. In some cases, eg., conda-forge desktop MPICH this is not the case and crashes. This adds the conditional d2h copies before speaking to MPI in those cases.
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## Summary Adds a new header `AMReX_GpuParallelReduce.H` which GPU-overloaded and support for MPIs with and without GPU-awareness (GPU-pointer support) in a safe manner. ## Additional background Added to prevent common usage bugs like BLAST-ImpactX/impactx#1532 ## Checklist The proposed changes: - [ ] fix a bug or incorrect behavior in AMReX - [x] add new capabilities to AMReX - [ ] changes answers in the test suite to more than roundoff level - [ ] are likely to significantly affect the results of downstream AMReX users - [ ] include documentation in the code and/or rst files, if appropriate
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A few of our reductions in collective effects where assuming we have GPU-aware MPI support. In some cases, eg., conda-forge desktop MPICH this is not the case and crashes. This adds the conditional d2h copies before speaking to MPI in those cases.
DeviceVectorAMReX-Codes/amrex#5516