## MPI API Trace

Nsight Systems is capable of capturing information about the MPI APIs executed in the profiled process. It has built-in API trace support only for the OpenMPI and MPICH implementations of MPI and only for a default list of synchronous APIs.

If you require more control over the list of traced APIs or if you are using a different MPI implementation, see github nvtx pmpi wrappers. You can use this documentation to generate a shared object to wrap a list of synchronous MPI APIs with NVTX using the MPI profiling interface (PMPI). If you set your LD_PRELOAD environment variable to the path of that object, Nsight Systems will capture and report the MPI API trace information when NVTX tracing is enabled.

NVTX tracing is automatically enabled when MPI trace is turned on.

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