Я очень новичок в программировании MPI, я пытаюсь запустить программу, которая должна сортировать, например, 8 или 16 или более чисел параллельно, я получаю ошибку сегментации, когда я компилирую и запускаю программу.Ниже приведен код, который я хочу скомпилировать.Любое предложение будет оценено.
#include <stdio.h>
#include <stdlib.h>
#include <mpi.h>
/* The IncOrder function that is called by qsort is defined as follows */
int IncOrder(const void *e1, const void *e2)
{
return (*((int *)e1) - *((int *)e2));
}
int main(int argc, char *argv[]){
int n; /* The total number of elements to be sorted */
int npes; /* The total number of processes */
int myrank; /* The rank of the calling process */
int nlocal; /* The local num of elements, and d array that stores */
int *elmnts; /* The array that stores the local elements */
int *relmnts; /* The array that stores the received elements */
int oddrank; /* The rank of d process during odd-phase comm */
int evenrank; /* The rank of the process during even-phase com */
int *wspace; /* Working space during the compare-split operation */
int i;
MPI_Status status;
/* Initialize MPI and get system information */
MPI_Init(&argc, &argv);
MPI_Comm_size(MPI_COMM_WORLD, &npes);
MPI_Comm_rank(MPI_COMM_WORLD, &myrank);
n = atoi(argv[1]);
nlocal = n/npes; /* Compute the number of elements to be stored locally. */
/* Allocate memory for the various arrays */
elmnts = (int *)malloc(nlocal*sizeof(int));
relmnts = (int *)malloc(nlocal*sizeof(int));
wspace = (int *)malloc(nlocal*sizeof(int));
/* Fill-in the elmnts array with random elements */
srandom(myrank);
for (i=0; i<nlocal; i++)
elmnts[i] = random();
/* Sort the local elements using the built-in quicksort routine */
qsort(elmnts, nlocal, sizeof(int), IncOrder);
/* Determine the rank of the processors that myrank needs to com during
* ics/ccc.gifthe */
/* odd and even phases of the algorithm */
if (myrank%2 == 0) {
oddrank = myrank-1;
evenrank = myrank+1;
} else {
oddrank = myrank+1;
evenrank = myrank-1;
}
/* Set the ranks of the processors at the end of the linear */
if (oddrank == -1 || oddrank == npes)
oddrank = MPI_PROC_NULL;
if (evenrank == -1 || evenrank == npes)
evenrank = MPI_PROC_NULL;
/* Get into the main loop of the odd-even sorting algorithm */
for (i=0; i<npes-1; i++) {
if (i%2 == 1) /* Odd phase */
MPI_Sendrecv(elmnts, nlocal, MPI_INT, oddrank, 1, relmnts,
nlocal, MPI_INT, oddrank, 1, MPI_COMM_WORLD, &status);
else /* Even phase */
MPI_Sendrecv(elmnts, nlocal, MPI_INT, evenrank, 1, relmnts,
nlocal, MPI_INT, evenrank, 1, MPI_COMM_WORLD, &status);
CompareSplit(nlocal, elmnts, relmnts, wspace, myrank < status.MPI_SOURCE);
}
MPI_Gather(elmnts,nlocal,MPI_INT,relmnts,n,MPI_INT,0,MPI_COMM_WORLD);
/* The master host display the sorted array */
int len = sizeof(elmnts)/sizeof(int);
if(myrank == 0) {
printf("\nSorted array :\n");
for (i=0;i<len;i++) {
printf("%d; ",relmnts[i]);
}
printf("\n");
}
free(elmnts); free(relmnts); free(wspace);
MPI_Finalize();
}
/* This is the CompareSplit function */
CompareSplit(int nlocal, int *elmnts, int *relmnts, int *wspace, int keepsmall){
int i, j, k;
for (i=0; i<nlocal; i++)
wspace[i] = elmnts[i]; /* Copy the elmnts array into the wspace array */
if (keepsmall) { /* Keep the nlocal smaller elements */
for (i=j=k=0; k<nlocal; k++) {
if (j == nlocal || (i < nlocal && wspace[i] < relmnts[j]))
elmnts[k] = wspace[i++];
else
elmnts[k] = relmnts[j++];
}
} else { /* Keep the nlocal larger elements */
for (i=k=nlocal-1, j=nlocal-1; k>=0; k--) {
if (j == 0 || (i >= 0 && wspace[i] >= relmnts[j]))
elmnts[k] = wspace[i--];
else
elmnts[k] = relmnts[j--];
}
}
}