[DO NOT MERGE] Initial NCCL Allreduce Backend Prototype #7298
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mjwilkins18
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This PR is a proof-of-concept of how we can use NCCL as a backend of MPI collectives. This PR is missing many necessary features and is not meant to be merged. I am interested in gathering feedback before continuing development. Some open questions/points for discussion I have: * When/where to properly init/free the `CCLcomm` structure * How to handle operation and data types portably (copy+pasting them into a new switch statement feels frail, and I am not 100% I covered all of the relevant datatypes) * How to design this extensibly so we can add RCCL, OneCCL, etc. (My intuition here is a base abstract class + derived classes, but this is not OOP.) * How to modify `src/mpi/coll/mpir_coll.c` to consider `CCL_Allreduce`. * How to pull-in NCCL from the environment and/or a configure argument `--with-nccl=` *Function/variable/file names and locations And anything else you can think of. Let me know what you think!
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Pull Request Description
This PR is a proof-of-concept of how we can use NCCL as a backend of MPI collectives. This PR is missing many necessary features and is not meant to be merged. I am interested in gathering feedback before continuing development. Some open questions/points for discussion I have:
CCLcommstructuresrc/mpi/coll/mpir_coll.cto considerCCL_Allreduce.--with-nccl=*Function/variable/file names and locations
And anything else you can think of. Let me know what you think!
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