July 1 2024

Attds: Hugo, Evan, Gabriel, Joseph, Carl, Matthew, Stephen, Vivek

Note-taker

Carl

still a bit hung up on https://github.com/kokkos/kokkos-comm/pull/81 (I think?) with regards to Kokkos::View of struct, and creating / releasing an MPI Derived Datatype
- decided to table the init/finalize stuff last week
https://github.com/kokkos/kokkos-comm/pull/100
- (Carl) start with 1st piece as it's own PR - keep send/recv in the API, move MPI stuff to KC::Mpi
- 3rd piece: plan is an optimization point. Maybe very minimal API supported inside plan.
- (Joseph): group instead of plan? or submit?
- (Joseph): returning vector of requests is challenging because if we do optimizations the number of requests and what each one means may change. Maybe just stream ordered, drop requests entirely - infrastructure in Kokkos may not exist for this?
- (Cedric): Kokkos graphs are experimental and might change a lot. Let's break up the PR.
https://github.com/kokkos/kokkos-comm/pull/89 needs a review (documentation)
The name
- put your suggestion in slack or the github discussion, we will have a formal vote this week
- https://github.com/kokkos/kokkos-comm/discussions/36

NCCL (Gabriel, Nicole, Evan)
- Gabriel
- I can try send/recv once the Transport PR is up
- NCCL missing collectives and how to implement it https://github.com/dssgabriel/sampik/blob/channels/docs/NCCL_OVERVIEW.md#example-implementation-of-collectives-using-p2p-calls
- Some NCCL stuff is quite similar but not exactly the same as MPI (MPI_IN_PLACE, MPI_ANY_SOURCE). MPI is not required to initialize NCCL, you just need a way to communicate unique IDs between ranks.
CI for GPUs (Carl)
- no update, waiting on name
Applications
- ArborX (Andrey)
Modern C++ / MPI
- P2300 sender/receiver accepted in committee https://isocpp.org/files/papers/P2300R10.html
  - Jospeh: interest in an API that fits P2300
Accelerator-Initiated Communication / Support
Smart NICs

Cedric: thinking about / mocking device-initiated communication with Gabriel
Vivek: anything nice we can do with tools here? Let's not miss any opportunities.