mpi_test

Various standalone C++ MPI tests/examples/benchmarks.

If CUDA is detected, additional binaries can be built.

name	Kind	Reqs.	Ranks	Description
hello-world	Test	MPI	1+	an MPI hello-world
one-sided	Test	MPI	2	one-sided communication
one-sided-gpu	Test	MPI+CUDA	2	one-sided communication on GPU buffer
persistent	Benchmark	MPI	2	ping-pong time for persistent Send/Recv
persistent-gpu	Benchmark	MPI+CUDA	2	ping-pong time for persistent Send/Recv on GPU buffer
send-recv	Benchmark	MPI	2	ping-pong time for Send/Recv
send-recv-gpu	Benchmark	MPI+CUDA	2	ping-pong time for Send/Recv on GPU buffer

Build

mkdir build && cd build
cmake ..
make

CMake will print the detected MPI environment. Confirm it is what you expect. For example:

-- MPI_VERSION:
-- MPI_CXX_COMPILER:            [...]/bin/mpicxx
-- MPI_CXX_COMPILE_OPTIONS:     -pthread
-- MPI_CXX_COMPILE_DEFINITIONS:
-- MPI_CXX_INCLUDE_DIRS:        [...]/include
-- MPI_CXX_LIBRARIES:           [...]/lib/libmpiprofilesupport.so;[...]/lib/libmpi_ibm.so
-- MPI_CXX_LINK_FLAGS:          -pthread

Examples

Summit

• 1 node: jsrun -n 1 ./persistent
• 2 nodes: jsrun -n 2 -r 1 -a 1 ./persistent
• 2 nodes w/GPU: jsrun --smpi="-gpu" -n 2 -r 1 -g 1 ./send-recv-gpu

Run all tests

run-all.sh attempts to discover certain environments automatically. You can always override the detected flags yourself if you want.

./run-all.sh | grep 'PASS\|FAIL'

If any tests fails, you can re-run them individually.

Run individual tests

Execute any binary you want using mpirun, or whatever is appropriate for your platform.

Notes on specific platforms

Some Open MPIs use long long for their datatypes, which is not a part of ANSI C++ (-ansi).