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
Ireduce_scatter
The benchmark for MPI_Ireduce_scatter that measures communication and computation overlap. It reduces a vector of length L = X/sizeof(float) float items. The MPI data type is MPI_FLOAT. The MPI operation is MPI_SUM. In the scatter phase, the L items are split as evenly as possible. To be exact, for np number of processes:
L = r*np+s
where
r = ⌊L/np⌋
s = L mod np
In this case, the process with rank i gets:
r+1 items when i<s
r items when is
Property |
Description |
---|---|
Measuredpattern |
MPI_Ireduce_scatter/IMB_cpu_exploit/MPI_Wait |
MPI data type |
MPI_FLOAT |
MPI operation |
MPI_SUM |
Reportedtimings |
For details, see Measuring Communication and Computation Overlap. |
Reportedthroughput |
None |