[mpich-discuss] Spawn MPI-Process

[Rajeev Thakur]

Instead of universe_size-1, try passing some number like 3 or 4.

Rajeev
 
On Aug 20, 2012, at 4:39 AM, Silvan Brändli wrote:

> Dear all
> 
> I try to start an application using the MPI_Comm_spawn command. However, when I execute my program I get a segmentation fault. I guess, this might be because universe_size is one. As I couldn't find helpful information on setting universe_size I hope some of you could help me.
> 
> Find the source code below or in the attached files. I compile the code using
> mpicxx main.cpp -o main
> mpicxx hi.cpp -o hi
> 
> and execute the case with
> 
> mpiexec -prepend-rank -np 1 ./main
> 
> The output is
> 
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
> 
> [0] world_size 1
> [0] universe size 1
> [0] try to spawn
> 
> =====================================================================================
> =   BAD TERMINATION OF ONE OF YOUR APPLICATION PROCESSES
> =   EXIT CODE: 11
> =   CLEANING UP REMAINING PROCESSES
> =   YOU CAN IGNORE THE BELOW CLEANUP MESSAGES
> =====================================================================================
> APPLICATION TERMINATED WITH THE EXIT STRING: Segmentation fault (signal 11)
> 
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
> 
> Best regards
> Silvan
> 
> $$$$==main.cpp==$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
> 
> #include <sstream>
> #include <mpi.h>;
> 
> using std::string;
> 
> int main(int argc, char *argv[])
> {
>  int          myrank;
>  if (MPI_Init(&argc,&argv)!=MPI_SUCCESS)
>  {
>    printf("MPI_Init failed");
>  }
>  MPI_Comm_rank(MPI_COMM_WORLD, &myrank);
> 
>  int world_size, universe_size, *universe_sizep, flag;
>  MPI_Comm_size(MPI_COMM_WORLD, &world_size);
>  printf("world_size %d\n",world_size);
> 
>  MPI_Attr_get(MPI_COMM_WORLD, MPI_UNIVERSE_SIZE,
>  &universe_sizep, &flag);
> 
>  if (!flag)
>  {
>    printf("This MPI does not support UNIVERSE_SIZE. How many processes total?");
>    scanf("%d", &universe_size);
>  } else universe_size = *universe_sizep;
>  printf("universe size %d\n",universe_size);
> 
>  char* hiargv[1];
>  char* m0=" ";
>  hiargv[0]=m0;
> 
>  MPI_Comm childComm;
>  int spawnerror;
>  printf("try to spawn\n");
>  MPI_Comm_spawn("./hi",hiargv, universe_size-1, MPI_INFO_NULL, myrank, MPI_COMM_SELF, &childComm, &spawnerror);
>  printf("after spawn\n");
>  MPI_Finalize();
>  return 0;
> }
> 
> $$$$==hi.cpp==$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
> 
> #include <mpi.h>;
> int main(int argc, char** argv) {
>  MPI_Init(NULL, NULL);
> 
>  int world_size;
>  MPI_Comm_size(MPI_COMM_WORLD, &world_size);
> 
>  int world_rank;
>  MPI_Comm_rank(MPI_COMM_WORLD, &world_rank);
> 
>  printf("Hello world from, rank %d"
>         " out of %d processors\n",
>         world_rank, world_size);
> 
>  MPI_Finalize();
>  return 0;
> }
> 
> $$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$
> -- 
> Dipl.-Ing. Silvan Brändli
> Numerische Strukturanalyse mit Anwendungen in der Schiffstechnik (M-10)
> 
> Technische Universität Hamburg-Harburg
> Schwarzenbergstraße 95c
> 21073 Hamburg
> 
> Tel.  : +49 (0)40 42878 - 6187
> Fax.  : +49 (0)40 42878 - 6090
> e-mail: silvan.braendli at tu-harburg.de
> www   : http://www.tuhh.de/skf
> 
> <main.cpp><hi.cpp>_______________________________________________
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