On 07/19/2013 05:26 PM, Sufeng Niu wrote:

MPI_Win_create(image_buff, 2*image_info->image_size * sizeof(uint16), sizeof(uint16), MPI_INFO_NULL, *MPI_FOR_WORLD, win); // MPI_FOR_WORLD is custom defined comm

Check if *MPI_FOR_WORLD is valid (or COMM_NULL).

I just free it as: MPI_Win_free(&win);

Check if win is valid (or WIN_NULL). In general, these are errors a debugger can catch. Please try that. -- Pavan -- Pavan Balaji http://www.mcs.anl.gov/~balaji