[OMPI users] mpi_rank : use as function arguments, or find it again every time

[Sefa Arslan]

Hi,

I need to use rank of the mpi processes in my sub functions ( c 
language). which one has more cost?;
   creating a new variable& and finding the rank in each sub function by:
       int mpi_rank;
       MPI_Comm_rank(MPI_COMM_WORLD,&mpi_rank);
   or finding the rank in main function once, and every time sending 
this information to the    functions in function arguments like
   foo(a,b,c,mpi_rank);