Dr. David Cronk Innovative Computing Lab University of ... - It works!

Collective Communication
Global Communication Routines:
› Except broadcast, each routine has 2 variants:
• Standard variant: All messages are the same size
• Vector Variant: Each item is a vector of possibly varying length
› If there is a single origin or destination, it is referred to as the
root
› Each routine (except broadcast) has distinct send and
receive arguments
› Send and receive buffers must be disjoint
› Each can use MPI_IN_PLACE, which allows the user to
specify that data contributed by the caller is already in its
final location.
David Cronk 86