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我試圖用奇數 - 即使換位排序隨機數字數組，但運行我的代碼時，我不斷收到一個分割錯誤：MPI調試段錯誤
[islb:48966] *** Process received signal ***
[islb:48966] Signal: Segmentation fault (11)
[islb:48966] Signal code: Address not mapped (1)
[islb:48966] Failing at address: 0x28
[islb:48966] [ 0] /lib64/libpthread.so.0(+0xf810)[0x7fc3da4cb810]
[islb:48966] [ 1] /lib64/libc.so.6(memcpy+0xa3)[0x7fc3da1c7cf3]
[islb:48966] [ 2] /usr/local/lib/libopen-pal.so.6(opal_convertor_unpack+0x10b)[0x7fc3d9c372db]
[islb:48966] [ 3] /usr/local/lib/openmpi/mca_pml_ob1.so(mca_pml_ob1_recv_request_progress_match+0x138)[0x7fc3d58507a8]
[islb:48966] [ 4] /usr/local/lib/openmpi/mca_pml_ob1.so(mca_pml_ob1_recv_req_start+0x1b1)[0x7fc3d5850d11]
[islb:48966] [ 5] /usr/local/lib/openmpi/mca_pml_ob1.so(mca_pml_ob1_recv+0x139)[0x7fc3d5849489]
[islb:48966] [ 6] /usr/local/lib/libmpi.so.1(MPI_Recv+0xc0)[0x7fc3da742f40]
[islb:48966] [ 7] oddEven[0x40115a]
[islb:48966] [ 8] /lib64/libc.so.6(__libc_start_main+0xe6)[0x7fc3da161c36]
[islb:48966] [ 9] oddEven[0x400c19]
[islb:48966] *** End of error message ***
--------------------------------------------------------------------------
mpirun noticed that process rank 1 with PID 48966 on node islb exited on signal 11 (Segmentation fault).
--------------------------------------------------------------------------
程序分配的陣列，它的當它將它分散到錯誤似乎發生的進程中，因爲直接在分散調用之後打印統計信息僅打印進程0，然後打印錯誤消息。
這裏是我的代碼：
#include <stdio.h>
#include <math.h>
#include <malloc.h>
#include <time.h>
#include <string.h>
#include "mpi.h"
const int MAX = 10000;
int myid, numprocs;
int i, n, j, k, arrayChunk, minindex;
int A, B;
int temp;
int swap(int *x, int *y) {
temp = *x;
*x = *y;
*y = temp;
return 0;
}
int main(int argc, char **argv) {
int* arr = NULL;
int* value = NULL;
MPI_Status status;
//int arr[] = {16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1};
srand(time(0));
time_t t1, t2;
MPI_Init(&argc, &argv);
MPI_Comm_rank(MPI_COMM_WORLD, &myid);
MPI_Comm_size(MPI_COMM_WORLD, &numprocs);
if (myid == 0) {
printf("Enter the number of elements you would like in the array \n");
scanf("%d", &n);
arrayChunk = n/numprocs;
//printf("cpus: %d, #s per cpu: %d\n", numprocs, arrayChunk);
//Allocate memory for the array
arr = malloc(n * sizeof(int));
value = malloc(n * sizeof(int));
// Generate an array of size n random numbers and prints them
printf("Elements in the array: ");
for (i = 0; i < n; i++) {
arr[i] = (rand() % 100) + 1;
printf("%d ", arr[i]);
}
printf("\n");
time(&t1);
}
if ((n % numprocs) != 0) {
if (myid == 0)
printf("Number of Elements are not divisible by numprocs \n");
MPI_Finalize();
return(0);
}
// Broadcast the size of each chunk
MPI_Bcast(&arrayChunk, 1, MPI_INT, 0, MPI_COMM_WORLD);
MPI_Scatter(&arr, arrayChunk, MPI_INT, &value, arrayChunk, MPI_INT, 0, MPI_COMM_WORLD);
printf("Processor %d receives %d\n", myid, value[0]);
for (i = 0; i < numprocs; i++) {
if (i % 2 == 0) {
if (myid%2 == 0) {
MPI_Send(&value[0], arrayChunk, MPI_INT, myid + 1, 0, MPI_COMM_WORLD);
MPI_Recv(&value[arrayChunk], arrayChunk, MPI_INT, myid + 1, 0, MPI_COMM_WORLD, &status);
for (j = 0; j < (arrayChunk * 2 - 1); j++) {
minindex = j;
for (k = j + 1; k < arrayChunk * 2; k++) {
if (value[k] < value[minindex]) {
minindex = k;
}
}
if (minindex > j) {
swap(&value[j], &value[minindex]);
}
}
//printf("myid %d i: %d, %d\n", myid, i, value[0]);
} else {
MPI_Recv(&value[arrayChunk], arrayChunk, MPI_INT, myid - 1, 0, MPI_COMM_WORLD, &status);
MPI_Send(&value[0], arrayChunk, MPI_INT, myid - 1, 0, MPI_COMM_WORLD);
for (j = 0; j < (arrayChunk * 2 - 1); j++) {
minindex = j;
for (k = j + 1; k < arrayChunk * 2; k++) {
if (value[k] < value[minindex]) {
minindex = k;
}
}
if (minindex > j) {
swap(&value[j], &value[minindex]);
}
}
for (j = 0; j < arrayChunk; j++) {
swap(&value[j], &value[j + arrayChunk]);
}
//printf("myid %d i: %d, %d\n", myid, i, value[0]);
}
} else {
if ((myid%2 == 1) && (myid != (numprocs-1))) {
MPI_Send(&value[0], arrayChunk, MPI_INT, myid + 1, 0, MPI_COMM_WORLD);
MPI_Recv(&value[arrayChunk], arrayChunk, MPI_INT, myid + 1, 0, MPI_COMM_WORLD, &status);
for (j = 0; j < (arrayChunk * 2 - 1); j++) {
minindex = j;
for (k = j + 1; k < arrayChunk * 2; k++) {
if (value[k] < value[minindex]) {
minindex = k;
}
}
if (minindex > j) {
swap(&value[j], &value[minindex]);
}
}
//printf("myid %d i: %d, %d\n", myid, i, value[0]);
} else if (myid != 0 && myid != (numprocs-1)) {
MPI_Recv(&value[arrayChunk], arrayChunk, MPI_INT, myid - 1, 0, MPI_COMM_WORLD, &status);
MPI_Send(&value[0], 1, MPI_INT, myid - 1, 0, MPI_COMM_WORLD);
for (j = 0; j < (arrayChunk * 2 - 1); j++) {
minindex = j;
for (k = j + 1; k < arrayChunk * 2; k++) {
if (value[k] < value[minindex]) {
minindex = k;
}
}
if (minindex > j) {
swap(&value[j], &value[minindex]);
}
}
for (j = 0; j < arrayChunk; j++) {
swap(&value[j], &value[j + arrayChunk]);
}
//printf("myid %d i: %d, %d\n", myid, i, value[0]);
}
}
}
MPI_Gather(&value[0], arrayChunk, MPI_INT, &arr[0], arrayChunk, MPI_INT, 0, MPI_COMM_WORLD);
if (myid == 0) {
time(&t2);
printf("Sorted array: ");
for (i = 0; i < n; i++) {
printf("%d ", arr[i]);
}
printf("\n");
printf("Time in sec. %f\n", difftime(t2, t1));
}
// Free allocated memory
if (arr != NULL) {
free(arr);
arr = NULL;
free(value);
value = NULL;
}
MPI_Finalize();
return 0;
}
我不是很熟悉C，它很可能是，我用malloc和/或地址和指針錯誤，因此它可能是簡單的東西。
對不起，我認爲最好是提供所有的代碼，以便進行適當的調試。
如果您提供可再現問題的_minimal_示例，則您更有可能獲得幫助。 –
這一行裏面的swap（）函數：'temp = * x;'正在使用全局變量'temp'使用本地/自動變量會更好：'int temp = * x;'注意：3個獨佔或操作會更快1）更快2）不需要'temp'的任何堆棧空間 – user3629249
這一行：arrayChunk = n/numprocs;正在執行整數除法。如果numprocs大於用戶輸入的'n'，那麼結果將永遠爲0 – user3629249