Hello MPI users,
first of all i want to introduce myself. My name is Florian Hahner and I'm
studying applied computer science in Fulda, Germany. In our class 'parallel
computing' I'm working at a MPI-2 Project to show the benefits and the working
method of one-sided communications.
I wrote a litte MPI program to demonstrate the mpi_get() function (see
attachment).
The idea behind the program is that a master process with rank 0 fills an
integer array with the size of MPI_Comm_size with values. The other processes
should MPI_GET the value from this shared int array at the index of their rank.
We could compile the code, but execution will raise an error.
We compile and run it with several MPI implementations (LAMMPI, MPICH ) and get
every time errors. Host system is: 5.10 Generic_150400-10 sun4u sparc
SUNW,SPARC-Enterprise Solaris
PS: I've some information are missing, please fill free to ask!
Best Regards
Florian Hahner
/*
* Beispiel Program für RMA mit MPI 2
* Beispiel Nr. 1
*
* Einfuehrung von MPI_Win_create()
* MPI_Win_fence() und MPI_get()
*
* Author Florian Hahner
* Datum 11. Jun 2014
* Version 1.0
*/
#include
#include
#include
int main(int argc, char** argv)
{
int rank, size, *a, *b, namelen, i, sizereal, flag;
char processor_name[MPI_MAX_PROCESSOR_NAME];
MPI_Win win;
MPI_Init(&argc, &argv); /* Initialisiere MPI Umgebung */
/* Ermittle den aktuellen Rang des Prozesses*/
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
/* Ermittle die Anzahl aller Prozesse im Communicator */
MPI_Comm_size(MPI_COMM_WORLD, &size);
/* Ermittle den Prozessornamen auf dem der akt. Prozess läuft */
MPI_Get_processor_name(processor_name, &namelen);
printf("Guten Tag. Ich bin Prozess %d von %d. Ich werde auf Host %s
ausgefuehrt\n", rank, size, processor_name);
/* Speicherreservierung für ein int-Arrays der Groesse size */
MPI_Alloc_mem(sizeof(int)*size, MPI_INFO_NULL, &a);
MPI_Alloc_mem(sizeof(int), MPI_INFO_NULL, &b);
if (rank==0)/* Master Prozess */
{
for(i = 0; i < size; i++)
{
a[i] = i * 100;
printf("a[%d]=%d\n", i, a[i]);
}
}
MPI_Win_create(a, size * sizeof(int), sizeof(int), MPI_INFO_NULL,
MPI_COMM_WORLD, &win);
printf ("ok1\n");
if (rank == 0)
{+
MPI_Win_get_attr(win, MPI_WIN_SIZE, &sizereal, &flag);
printf ("ok2\n");
if (flag == 0)
{
printf ("MPI_Win_get_attr(): Unknown attribute\n");
exit (EXIT_FAILURE);
}
else
{
printf("Real Size %d\n", sizereal);
}
}
else
{
printf ("Process %d after MPI_Win_create()\n");
}
printf ("ok3\n");
/* Erstellen des lokalen Speicherfensters */
/* Das Speicherfenster zeigt auf den Adressraum des */
/* int-Arrays a. Es hat die GröÃe von size*sizeof(int)*/
/* und nutze das Window Objekt win */
MPI_Win_fence(0, win);
if (rank>0)
{
MPI_Get(b, 1, MPI_INT, 0, rank, 1, MPI_INT, win);
}
MPI_Win_fence(0, win);
if (rank>0)
{
printf("Prozess %d# hat Wert %d von Prozess 0 geholt\n", rank, b);
}
MPI_Win_free(&win);
MPI_Free_mem(a);
MPI_Finalize();
}
