链接在库中,包含对cuda内核的引用

Question

我试图找出如何使用CUDA内核作为库的一部分,以便我可以将库添加到我现有的C++源文件,并能够使用cuda内核.

那么你怎么做呢？我尝试创建一个包装器,如下所示:

.h文件:

#ifndef __reductions2d_H_
#define __reductions2d_H_
#include <stdio.h>
#include <cuda.h>
#include <cuda_runtime.h>
extern "C" void getMean_wrapper();
#endif

.CU

 __global__ void getMean(float *devDataPtr, size_t pitch, int rows, int cols)
       {
          for (int r = 0; r < height; ++r)
          { 
             float* row = (float*)((char*)devPtr + r * pitch);
             for (int c = 0; c < width; ++c)
             {
                printf("Row[%i][%i]: %4.3f \n",r,c row[c]);
             }
          }
       }


   void getMean_wrapper()
   {
   // Host code 
     int width = 3, height = 3;
     int N = width*height;
     float* devData; size_t pitch;
     cudaMallocPitch(&devData, &pitch, width * sizeof(float),height);
     int blockSize = 4;
     int nBlocks = N/blockSize + (N%blockSize == 0?0:1);

     getMean<<<nBlocks, blockSize>>>(devData, pitch, width,height);
   }

main.cpp中

#include "reductions2d.h"

int main(void){

getMean_wrapper();
return 0;

}

但是,当我用nvcc*.cpp编译它时,它告诉我它找不到getMean_wrapper(),当我尝试用g ++ -c main.cpp编译时,它告诉我它找不到cuda.h和cuda_runtime.h

使用我的G ++命令行指定cuda库的位置,构建这些对象,构建.cu对象,然后链接它们是最好的方法吗？看起来像是一个麻烦,必须有一个3步骤的过程来添加一些cuda功能

谢谢

编辑:

看起来当我尝试单独进行时,就像链接一样

g++ -o runme *.o -lcuda

我明白了

$ g++ -o runme *.o -lcuda
reductions2d.o: In function         `__sti____cudaRegisterAll_47_tmpxft_00007643_00000000_4_reductions2d_cpp1_ii_4ef 611a7()':
tmpxft_00007643_00000000-1_reductions2d.cudafe1.cpp:(.text+0x15e): undefined     reference to `__cudaRegisterFatBinary'
tmpxft_00007643_00000000-1_reductions2d.cudafe1.cpp:(.text+0x1b9): undefined reference to `__cudaRegisterFunction'
reductions2d.o: In function `__cudaUnregisterBinaryUtil()':
tmpxft_00007643_00000000-1_reductions2d.cudafe1.cpp:(.text+0x1d8): undefined reference to `__cudaUnregisterFatBinary'
reductions2d.o: In function `__device_stub__Z7getMeanPfmii(float*, unsigned long, int, int)':
tmpxft_00007643_00000000-1_reductions2d.cudafe1.cpp:(.text+0x20d): undefined reference to `cudaSetupArgument'
tmpxft_00007643_00000000-1_reductions2d.cudafe1.cpp:(.text+0x22f): undefined reference to `cudaSetupArgument'
tmpxft_00007643_00000000-1_reductions2d.cudafe1.cpp:(.text+0x251): undefined reference to `cudaSetupArgument'
tmpxft_00007643_00000000-1_reductions2d.cudafe1.cpp:(.text+0x273): undefined reference to `cudaSetupArgument'
reductions2d.o: In function `getMean_wrapper':
tmpxft_00007643_00000000-1_reductions2d.cudafe1.cpp:(.text+0x164c): undefined reference to `cudaConfigureCall'
reductions2d.o: In function `cudaError cudaLaunch<char>(char*)':
tmpxft_00007643_00000000-1_reductions2d.cudafe1.cpp:(.text._Z10cudaLaunchIcE9cudaErrorPT_[cudaError cudaLaunch<char>(char*)]+0x11): undefined reference to `cudaLaunch'
reductions2d.o: In function `cudaError cudaMallocPitch<float>(float**, unsigned long*, unsigned long, unsigned long)':
tmpxft_00007643_00000000-1_reductions2d.cudafe1.cpp:(.text._Z15cudaMallocPitchIfE9cudaErrorPPT_Pmmm[cudaError cudaMallocPitch<float>(float**, unsigned long*, unsigned long, unsigned long)]+0x29): undefined reference to `cudaMallocPitch'

我读到我需要包含cuda运行时库,所以我做了

ldconfig -p | grep cudart并在我的LD_LIBRARY_PATH中包含了/ usr/local/cuda/lib64,它仍然无法找到cudart

Answer 1

包括.h进.cu为好.nvcc是c ++编译器和mangles名称.

编译为:

nvcc -c file.cu // compile cuda kernel
nvcc file.o main.cpp // compile and link

我会把你的代码更改为:

.HPP

#ifndef __reductions2d_H_
#define __reductions2d_H_

void getMean_wrapper(); // c++ linkga

#endif

.CU:

#include "...hpp"
#include <cuda.h>
#include <cuda_runtime.h>

__global__ void getMean(float *devDataPtr, size_t pitch, int rows, int cols)
   {

然后你编译为

nvcc -c file.cu // compile cuda kernel
g++ -lcudart file.o main.cpp // no cuda stuff needed save for lib