Hi all, I am trying to scatter data from the master process to the others using scatterv and my own datatype that maps out the blocks of data in memory.
The problem is that I dont know what unit size the function (scatterv) is using to measure displacements in. I assume that it is using the extent of the user-defined datatype, but I need to specify the displacements in bytes. For example, if I specify a displacement of 2 from the sendbuffer, does this mean 2 bytes or 2*MPI_Type_size() or 2*MPI_Type_extent()? The man page isn't very clear on this. I know that there is function MPI_Type_hindexed, that accepts displacements measured is bytes when creating new datatypes. Is there something similar for scatterv/gatherv? Thanks.
