複製由cudaMallocPitch分配的內存

Question

可以使用cudaMemcpy分配與cudaMallocPitch分配的內存嗎？如果不是，你能告訴，應該使用哪個函數。 cudaMallocPitch返回線性內存，所以我想應該使用cudaMemcpy。

Answer 1

您當然可以使用cudaMemcpy複製傾斜的設備內存，但使用cudaMemcpy2D更爲常用。從主機到設備投副本的一個例子是這個樣子：

#include "cuda.h" 
#include <assert.h> 

typedef float real; 

int main(void) 
{ 

    cudaFree(0); // Establish context 

    // Host array dimensions 
    const size_t dx = 300, dy = 300; 

    // For the CUDA API width and pitch are specified in bytes 
    size_t width = dx * sizeof(real), height = dy; 

    // Host array allocation 
    real * host = new real[dx * dy]; 
    size_t pitch1 = dx * sizeof(real); 

    // Device array allocation 
    // pitch is determined by the API call 
    real * device; 
    size_t pitch2; 
    assert(cudaMallocPitch((real **)&device, &pitch2, width, height) == cudaSuccess); 

    // Sample memory copy - note source and destination pitches can be different 
    assert(cudaMemcpy2D(device, pitch2, host, pitch1, width, height, cudaMemcpyHostToDevice) == cudaSuccess); 

    // Destroy context 
    assert(cudaDeviceReset() == cudaSuccess); 

    return 0; 
} 

（注：未經測試，cavaet自負和所有.....）