Mpi与Cuda混合编程（Makefile）
需要建立一个.c的MPI程序和一个.cu的CUDA程序，MPI程序中调用CUDA中的函数来完成并行与GPU的混合编程，我查询了很多资料和博客，最终得出结论，还是Google比较强大，百度什么的还是搜不到完整的讲解
MPI程序如下（文件名test.c）
#include
#include
#include
#include
#include "mpi.h"
void fun ( float * vp_device , int n , int nz , int is) ;
void cudaFun ( int is , FILE *fp, int nx , int nz ) ;
main( int argc, char *argv[ ] )
{
int myid , numprocs , count , is , nx , nz ;
float * vp;
nx = 1000 ; nz = 1000 ;
MPI_Init(&argc,&argv);
MPI_Comm_rank(MPI_COMM_WORLD,&myid);
MPI_Comm_size(MPI_COMM_WORLD,&numprocs);
MPI_Barrier(MPI_COMM_WORLD);
FILE *fp;
fp=fopen( "test.dat" , "wb" );
for ( is = myid ; is < 10 ; is = is + numprocs )
{
printf( " is== %d \n " , is ) ;
cudaFun( is , fp , nx , nz );
}
MPI_Finalize( );
} CUDA程序如下（文件名test_cuda.cu）
#include
#include
#include
#include
#include
__device__ volatile int vint = 0;
//a#########################
extern "C" __global__ void fun ( float * vp_device , int n, int nz, int is )
{
int it=threadIdx.x blockDim.x*blockIdx.x;
if ( it < n ) {
vp_device[it]=2000;
if ( ( it > nz * 40 && it < 40 && it % nz < 60 ) )
vp_device [ it ] = 2500 * is * 100 ;
}
}
//a########################
extern "C" void cudaFun ( int is , FILE *fp , int nx , int nz )
{
int i ;
float * vp_device , * vp_host;
cudaMalloc(&vp_device, nx*nz*sizeof(float));
cudaMemset(vp_device, 0, nx*nz*sizeof(float));
vp_host=(float*)malloc(nx*nz*sizeof(float));
float mstimer;
cudaEvent_t start, stop;
cudaEventCreate(&start);
cudaEventCreate(&stop);
fun <<<( nx * nz + 511 ) / 512, 512>>> ( vp_device , nx*nz , nz , is ) ;
cudaMemcpy(vp_host, vp_device, nx*nz*sizeof(float),cudaMemcpyDeviceToHost);
fseek(fp,is*nx*nz*sizeof(float),0);
for ( i = 0 ; i < nx * nz ; i ++ )
fwrite( &vp_host[i] , sizeof(float) , 1 , fp);
cudaEventRecord(stop);
cudaEventSynchronize(stop);
cudaEventElapsedTime(&mstimer, start, stop);
printf( "CUDA : is = %d, time = %g (s)\ n " ,is, mstimer*1.e-3);
cudaEventDestroy(start);
cudaEventDestroy(stop);
cudaFree(vp_device);
free(vp_host);
}
Makefile如下（文件名Makefile）
CUDA_INSTALL_PATH = /usr/local/cuda-7.5
MPI_INSTALL_PATH = /home/leonvel/software/mpi/mpich
NVCC = $(CUDA_INSTALL_PATH)/bin/nvcc
MPICC = $(MPI_INSTALL_PATH)/bin/mpicc
LDFLAGS = -L$(CUDA_INSTALL_PATH)/lib64
LIB = -lcudart -lcurand
CFILES = test.c
CUFILES = test_cuda.cu
OBJECTS = test.o test_cuda.o
EXECNAME = test
all:
$(MPICC) -c $(CFILES)
$(NVCC) -c $(CUFILES)
$(MPICC) -o $(EXECNAME) $(LDFLAGS) $(LIB) $(OBJECTS)
clean:
rm -f *.o $(EXECNAME)我的环境是Linux，所以接下来make一下吧，
[Toa@AMAX test]$ make
/home/leonvel/software/mpi/mpich/bin/mpicc -c test.c
/usr/local/cuda-7.5/bin/nvcc -c test_cuda.cu
/home/leonvel/software/mpi/mpich/bin/mpicc -o test -L/usr/local/cuda-7.5/lib64 -lcudart -lcurand test.o test_cuda.o
然后我们在运行一下：
[Toa@AMAX test]$ ./test
is==0
CUDA:is=0, time= 0 (s)
is==1
CUDA:is=1, time= 0 (s)
is==2
CUDA:is=2, time= 0 (s)
is==3
CUDA:is=3, time= 0 (s)
is==4
CUDA:is=4, time= 0 (s)
is==5
CUDA:is=5, time= 0 (s)
is==6
CUDA:is=6, time= 0 (s)
is==7
CUDA:is=7, time= 0 (s)
is==8
CUDA:is=8, time= 0 (s)
is==9
CUDA:is=9, time= 0 (s)
[Toa@AMAX test]$没错，你没看错，运行时间就是零秒钟，就是这么快，就是这么尿性。好的，我今天的工作就是这么多，等以后继续学习的时候我会继续更新的，拜拜了，伙计们。。。。。
