编辑:我的问题类似于C, Open MPI: segmentation fault from call to MPI_Finalize(). Segfault does not always happen, especially with low numbers of processes,所以你回答那一个,而不是那么好,无论哪种方式。 。 。MPI调试,分段错误?
我希望能得到一些帮助调试以下代码:
int main(){
long* my_local;
long n, s, f;
MPI_Init(NULL, NULL);
MPI_Comm_size(MPI_COMM_WORLD, &comm_sz);
MPI_Comm_rank(MPI_COMM_WORLD, &my_rank);
if(my_rank == 0){
/* Get size n from user */
printf("Total processes: %d\n", comm_sz);
printf("Number of keys to be sorted? ");
fflush(stdout);
scanf("%ld", &n);
/* Broadcast size n to other processes */
MPI_Bcast(&n, 1, MPI_LONG, 0, MPI_COMM_WORLD);
/* Create n/comm_sz keys
NOTE! some processes will have 1 extra key if
n%comm_sz != 0 */
create_Keys(&my_local, my_rank, comm_sz, n, &s, &f);
}
if(my_rank != 0){
/* Receive n from process 0 */
MPI_Bcast(&n, 1, MPI_LONG, 0, MPI_COMM_WORLD);
/* Create n/comm_sz keys */
create_Keys(&my_local, my_rank, comm_sz, n, &s, &f);
}
/* The offending function, f is a long set to num elements of my_local*/
Odd_Even_Tsort(&my_local, my_rank, f, comm_sz);
printf("Process %d completed the function", my_rank);
MPI_Finalize();
return 0;
}
void Odd_Even_Tsort(long** my_local, int my_rank, long my_size, int comm_sz)
{
long nochange = 1;
long phase = 0;
long complete = 1;
MPI_Status Stat;
long your_size = 1;
long* recv_buf = malloc(sizeof(long)*(my_size+1));
printf("rank %d has size %ld\n", my_rank, my_size);
while (complete!=0){
if((phase%2)==0){
if(((my_rank%2)==0) && my_rank < comm_sz-1){
/* Send right */
MPI_Send(&my_size, 1, MPI_LONG, my_rank+1, 0, MPI_COMM_WORLD);
MPI_Send(*my_local, my_size, MPI_LONG, my_rank+1, 0, MPI_COMM_WORLD);
MPI_Recv(&your_size, 1, MPI_LONG, my_rank+1, 0, MPI_COMM_WORLD, &Stat);
MPI_Recv(&recv_buf, your_size, MPI_LONG, my_rank+1, 0, MPI_COMM_WORLD, &Stat);
}
if(((my_rank%2)==1) && my_rank < comm_sz){
/* Send left */
MPI_Recv(&your_size, 1, MPI_LONG, my_rank-1, 0, MPI_COMM_WORLD, &Stat);
MPI_Recv(&recv_buf, your_size, MPI_LONG, my_rank-1, 0, MPI_COMM_WORLD, &Stat);
MPI_Send(&my_size, 1, MPI_LONG, my_rank-1, 0, MPI_COMM_WORLD);
MPI_Send(*my_local, my_size, MPI_LONG, my_rank-1, 0, MPI_COMM_WORLD);
}
}
phase ++;
complete = 0;
}
printf("Done!\n");
fflush(stdout);
}
而我得到的错误是:
[ubuntu:04968] *** Process received signal ***
[ubuntu:04968] Signal: Segmentation fault (11)
[ubuntu:04968] Signal code: Address not mapped (1)
[ubuntu:04968] Failing at address: 0xb
--------------------------------------------------------------------------
mpiexec noticed that process rank 1 with PID 4968 on node ubuntu exited on signal 11 (Segmentation fault).
我困惑的原因是,报表的打印功能仍然显示之后,但如果我注释掉这个功能,没有错误。那么,我在哪里得到分段错误?我遇到了mpiexec -n 2 ./a.out和n大于9的错误。
如果您确实需要整个可运行代码,请告诉我。真的,我希望没有那么确切的答案,但更多的是如何使用gdb/valgrind工具来调试这个问题和其他类似的问题(以及如何读取它们的输出)。
(是的,我意识到“排序”功能尚未排序)。这里
“该功能后的打印语句仍然显示,但如果我注释掉该功能,则无错误”。这表明你的函数做了错误的事情,后来就成了一个错误。尝试在代码的重要阶段放置屏障和打印,并查看执行得到的程度。 – suszterpatt