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Measuring Communication and Computation Overlap
Measuring Pure Communication Time
Iallgather
Iallgather_pure
Iallgatherv
Iallgatherv_pure
Iallreduce
Iallreduce_pure
Ialltoall
Ialltoall_pure
Ialltoallv
Ialltoallv_pure
Ibarrier
Ibarrier_pure
Ibcast
Ibcast_pure
Igather
Igather_pure
Igatherv
Igatherv_pure
Ireduce
Ireduce_pure
Ireduce_scatter
Ireduce_scatter_pure
Iscatter
Iscatter_pure
Iscatterv
Iscatterv_pure
Exchange
Exchange is a communication pattern that often occurs in grid splitting algorithms (boundary exchanges). The group of processes is similar to a periodic chain, and each process exchanges data with both left and right neighbor in the chain.
The turnover count is four messages per sample (two in, two out) for each process.
For two Isend messages, separate buffers are used.
Exchange Definition
Property |
Description |
---|---|
Measured pattern |
As symbolized between |
MPI routines |
MPI_Isend/MPI _Waitall, MPI_Recv |
MPI data type |
MPI_BYTE |
Reported timings |
time=Δt (in μsec) |
Reported throughput |
4X/time |
Exchange Pattern
