The MPI_Alltoallv operation sends a message from every
node to every node. In addition to the ``normal''
MPI_Alltoall operation here we able to specify which data from a
process' sending buffer should be send to any other process (send
displacement and send lengths) and we can specify where a process'
data received from any other process should be stored (receive
displacement and receives lengths). We vary over the number of nodes.
The messages have the length of 256 Bytes (for each node).
Pattern: Collective varied over number of nodes.
default values: 8 nodes, message length 256 units, max. / act. time for suite disabled/0.00 min.