CPU下的计时与GPU计时对比

1.CPU下：使用clock_t统计时间

clock_t start;clock_t end;start=clock();filter2D (outimage,B,-1,fx);//这是要统计时间的函数end=clock();double time=(double)(end-start)/CLOCKS_PER_SEC;printf("\n");cout<<"原函数 filter2D 的执行时间 is: "<<time*1000<<"ms"<<endl;

1. GPU下：使用cudaEventCreate统计时间

cudaEventCreate(&start);cudaEventCreate(&stop);cudaEventRecord(start,0);kernel_filter2D<<<grid, block>>>(width,height,byteCount,d_src_imgbuf,d_filter2D_imgbuf);cudaEventRecord(stop, 0);cudaEventSynchronize(start);cudaEventSynchronize(stop);cudaEventElapsedTime(&time,start,stop);cudaEventDestroy(start);cudaEventDestroy(stop);printf("GPU下 filter2D 的执行时间：%f(ms)\n",time);