【发布时间】：2014-01-08 03:01:24
【问题描述】：
我目前正在使用 mpi 开发用于矩阵乘法的 C 代码。我已经将函数实现为在其他文件中定义的 mult 或 multadd，运行良好。
但是我的文件pblas.c 可以编译，但运行时崩溃。
我在安装了mli 的大学服务器上运行我的项目。
我的pblas 代码哪里错了？
/**********************************************************************
This file is just a pattern for pblas parallel multiplication
There are comments beginning with TO ADD that tell what must be done
where they are placed. Thus, just add the correct lines of code and
everything will work fine !
*********************************************************************/
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <time.h>
#include <math.h>
#include <string.h>
#include "commfct.h"
#include "toolsfct.h"
void usage() {
fprintf(stderr,"usage : pblas bloc_size\n\t bloc_size : gives the size of blocs owned by each processor.\n");
exit(1);
}
int main(int argc, char **argv) {
int me,nbProc;
int ligMe,colMe;
int blockSize;
int i,j;
double t;
if (argc != 2) {
usage();
}
blockSize = atoi(argv[1]);
MPI_Init(&argc, &argv);
MPI_Comm_rank(MPI_COMM_WORLD, &me);
MPI_Comm_size(MPI_COMM_WORLD, &nbProc);
int P = (int)sqrt(nbProc); // P = the number of rows of proc.
int Q = P; // Q = the number of columns of proc.
if ((P*Q) != nbProc) {
if (me == 0) {
fprintf(stderr,"!!! CRITICAL ERROR : number of processors must be 4, 9, 16, ...\nAborting\n");
}
exit(1);
}
createGridComm(me,P,Q);
ligMe = me / Q;
colMe = me % Q;
// allocate memory for matrices
double *A,*Btmp, *B,*C,*CC;
A = (double *)malloc(blockSize*blockSize*sizeof(double));
B = (double *)malloc(blockSize*blockSize*sizeof(double));
Btmp = (double *)malloc(blockSize*blockSize*sizeof(double));
C = (double *)malloc(blockSize*blockSize*sizeof(double));
CC = (double *)malloc(blockSize*blockSize*sizeof(double));
/* fill blocks with pseudo values
NOTE : these values should not be changed so that
the check below is valid
*/
for(i=0;i<blockSize*blockSize;i++) {
A[i] = 2.0+(double)me;
B[i] = 1.0+(double)colMe;
C[i] = (double)me / 10.0;
}
/* CAUTION : in the following, A,B C are supposed to be stored
column after column, with each column of size blockSize.
Thus A(0,0) and A(1,0) are contiguous in memory, but
A(0,0) and A(0,1) are separated by blockSize cells.
*/
t = dclock(CLOCK_S);
MPI_Status status;
//main Loop
for(i=0;i<P;i++) {
/*************************************
Etape 1 et 2: Transposition column i (in step i) of B-blocks . stock in Btmp.
**************************************/
if(colMe==i){
if(ligMe==colMe) {
MPI_Bcast(Btmp,blockSize*blockSize,MPI_DOUBLE,ligMe,commCol);
multadd(A,B,C,blockSize);
}
else {
int dest = colMe * Q + ligMe;
MPI_Send(B,blockSize*blockSize,MPI_DOUBLE,dest,TAG_TRANSPOSE, MPI_COMM_WORLD);
MPI_Bcast(Btmp,blockSize*blockSize,MPI_DOUBLE,dest%Q,commCol);
mult(A,Btmp,CC,blockSize);
}
}
else {
int dest = colMe*Q + ligMe;
if(dest%Q == i) {
MPI_Recv(Btmp,blockSize*blockSize,MPI_DOUBLE,dest,TAG_TRANSPOSE,MPI_COMM_WORLD,&status);
// Broadcast on the column
MPI_Bcast(Btmp,blockSize*blockSize,MPI_DOUBLE,colMe,commCol);
multadd(A,Btmp,C,blockSize);
}
else {
MPI_Bcast(Btmp,blockSize*blockSize,MPI_DOUBLE,i,commCol);
mult(A,Btmp,CC,blockSize);
}
}
if(colMe == i)
MPI_Reduce(MPI_IN_PLACE, C, blockSize*blockSize, MPI_DOUBLE, MPI_SUM, colMe, commLine);
else
MPI_Reduce(CC,NULL,blockSize*blockSize,MPI_DOUBLE,MPI_SUM,i,commLine);
}
t = dclock(CLOCK_S) -t;
printf("timing for %d : %f sec\n",me,t);
// checking for result correctness
int correct = 1;
double sum = 0.0;
for(i=0;i<P;i++) {
sum += 2.0+(ligMe*Q)+(double)i;
}
for(i=0;i<blockSize;i++) {
for(j=0;j<blockSize;j++) {
if (C[i+j*blockSize] != ((double)me/10.0 + sum*blockSize*(colMe+1.0))) {
correct = 0;
}
}
}
if (correct != 1) {
printf("multiplication result is not correct\n");
}
// free memory
free(A);
free(B);
free(C);
free(CC);
releaseGridComm();
MPI_Finalize();
return 0;
}
【问题讨论】：
-
你知道它崩溃在哪一行吗？
-
更多关于您尝试过的指导。确切的错误是什么以及它发生的位置等是需要的。如果你不让它变得更容易，在这里仅仅调试其他人的代码并不是很有趣。
标签： c matrix mpi distributed-computing