MPI shared memory #14
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hmenke
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Oct 9, 2023
hmenke
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Aug 16, 2024
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| // Expose some commonly used attributes | ||
| BaseType* base() const noexcept { return static_cast<BaseType*>(get_attr(MPI_WIN_BASE)); } | ||
| MPI_Aint size() const noexcept { return *static_cast<MPI_Aint*>(get_attr(MPI_WIN_SIZE)); } | ||
| int disp_unit() const noexcept { return *static_cast<int*>(get_attr(MPI_WIN_DISP_UNIT)); } | ||
| }; |
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Can these function calls be turned into members that are initialized at construction?
hmenke
commented
Aug 16, 2024
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| /// Load data from a remote memory window. | ||
| template <typename TargetType = BaseType, typename OriginType> | ||
| std::enable_if_t<has_mpi_type<OriginType> && has_mpi_type<TargetType>, void> |
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Replace std::enable_if with requires.
hmenke
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Aug 16, 2024
hmenke
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Aug 16, 2024
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| void free() noexcept { | ||
| if (win != MPI_WIN_NULL) { | ||
| MPI_Win_free(&win); |
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Check that MPI_Win_free is indeed blocking on all ranks.
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All tests were run with multiple nodes and different number of slots on each node:
Some ideas:
MPI allocatorSimilar to
std::allocatorimplement ashared_allocatorand adistributed_shared_allocator, such that one can use e.g.std::vector<double, mpi::shared_allocator<double>>Questions:
split_shared()on the default communicator, but for distributed shared memory there needs to be internode communication and that is not easily guessed from the default communicator. Maybe a global hash table with allocation information is needed?On top of that, for distributed shared memory access must be fenced and broadcasted between nodes. That's not so easy to abstract away.