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mpiopenmpi

Count parameter in MPI_Bcast

MPI_Bcast (&buffer,count,datatype,root,comm)

The tutorial at https://computing.llnl.gov/tutorials/mpi/ says that count - Indicates the number of data elements of a particular type to be sent.

What does that mean? Does it mean that -

  1. count copies of the buffer array will be sent

    OR

  2. count elements of the buffer is to be sent?

Solution

  • It's the second one. count elements of sizeof(datatype) will be sent.