50 lines
1.8 KiB
Plaintext
50 lines
1.8 KiB
Plaintext
#include <chrono>
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#include <cstdio>
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#define CHECK_CUDA(call) \
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do { \
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cudaError_t status_ = call; \
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if (status_ != cudaSuccess) { \
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fprintf(stderr, "CUDA error (%s:%d): %s:%s\n", __FILE__, __LINE__, \
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cudaGetErrorName(status_), cudaGetErrorString(status_)); \
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exit(EXIT_FAILURE); \
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} \
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} while (0)
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__global__ void init(int *a) {
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int i = blockIdx.x * blockDim.x + threadIdx.x;
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a[i] = i;
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}
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int main() {
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int *d_a, *a, *a_pinned;
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CHECK_CUDA(cudaMalloc(&d_a, sizeof(int) * (1 << 20)));
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CHECK_CUDA(cudaMallocHost(&a_pinned, sizeof(int) * (1 << 20)));
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a = (int *) malloc(sizeof(int) * (1 << 20));
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for (int i = 0; i < (1 << 20); ++i) { a[i] = i; }
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init<<<(1 << 15), 32>>>(d_a);
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CHECK_CUDA(cudaDeviceSynchronize());
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{
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auto start = std::chrono::system_clock::now();
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CHECK_CUDA(
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cudaMemcpy(a, d_a, sizeof(int) * (1 << 20), cudaMemcpyDeviceToHost));
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auto end = std::chrono::system_clock::now();
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std::chrono::duration<double> diff = end - start;
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printf("Pageable memory bandwidth: %lf GB/s\n",
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(sizeof(int) / diff.count() / 1000.));
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}
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{
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auto start = std::chrono::system_clock::now();
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CHECK_CUDA(cudaMemcpy(a_pinned, d_a, sizeof(int) * (1 << 20),
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cudaMemcpyDeviceToHost));
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auto end = std::chrono::system_clock::now();
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std::chrono::duration<double> diff = end - start;
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printf("Pinned memory bandwidth: %lf GB/s\n",
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(sizeof(int) / diff.count() / 1000.));
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}
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return 0;
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}
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