将字符映射表从主机内存复制到 CUDA 中的设备

Question

不确定如何将其从主机内存复制到设备内存，已经研究了一段时间但没有取得任何进展，任何大大小小的帮助将不胜感激。

 unsigned char map[256] = {

   8,0,2,0,0,0,0,0,0,0,2,0,2,0,0,0,
   0,0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,
   0,0,0,0,0,0,0,0,0,0,0,0,0,7,0,0,
   0,0,0,1,0,0,0,0,0,0,0,0,0,0,0,0,
   0,0,0,0,0,1,0,0,0,0,0,0,0,0,0,0,
   0,0,0,1,1,1,0,0,0,0,0,0,0,0,0,0,
   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
   0,2,0,0,0,1,0,0,0,0,0,0,0,1,0,0,
   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
   0,0,0,0,0,0,0,0,2,0,0,0,0,0,0,0,
   0,1,1,1,0,0,0,0,0,0,0,0,3,0,0,0,
   0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
   0,0,0,1,0,0,0,5,0,0,0,3,0,0,0,0,
   0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,
 };

会和这个类似吗？

cudaMalloc(&d_n, sizeof(int));

  cudaMemcpy(d_n, &h_n, sizeof(int), cudaMemcpyHostToDevice);

  kernel <<<16,16>>>(d_n);

  cudaThreadSynchronize();

  cudaMemcpy(&h_n, d_n, sizeof(int), cudaMemcpyDeviceToHost);  

  cudaFree(d_n);

Answer 1

如果您的代码中存在段错误，这可能是由于以下错误造成的:

1. 您正在使用 sizeof(int) 复制无符号字符数组。

2. h_n 您的数组名为“map”吗？ unsigned char[] 是一个指针，您可以直接在 cudaMemcpy 方法中使用它。

   cudaMemcpy(d_n, map, 256 * sizeof(unsigned char), cudaMemcpyHostToDevice);

应该可以。