Newsgroups: comp.parallel.mpi
From: Vinod Mathur <vinod.mathur@lawson.com>
Reply-To: vinod.mathur@lawson.com
Subject: MPICH & WMPI: Segmentation Violation in MPI_Cart_sub()
Organization: Lawson Software
Date: Fri, 20 Feb 1998 08:12:20 -0600
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Message-ID: <34ED8F44.682@lawson.com>

I wrote a program using a mesh topology and
wanted to use MPI_Cart_sub() for creating sub
topologies. I get a segmentation violation in MPICH
and an 0 memory reference exception in cvwmpi.dll. I've 
ensured that the parameters to the function are correct. 
Has someone encountered similar problems?

code snippets are.....
..............
......
MPI_Comm	Comm_World_Mesh;		/* Communicator for mesh topology */
MPI_Comm Comm_World_Sub_Cart;
..............
......
if(MPI_Cart_create(MPI_COMM_WORLD, 2, DimensionSize, Periods, 1,
&Comm_World_Mesh)!= MPI_SUCCESS)
{	
......../* error handling */.........
}
...........
.......
KeepDims4SubCart[ROW] = 1;
KeepDims4SubCart[COL] = 0;
if(MPI_Cart_sub(Comm_World_Mesh, KeepDims4SubCart,
&Comm_World_Sub_Cart)!= MPI_SUCCESS)
{
......../* error handling */.........
}
...  call above blows up.....
..............