Output of cuda program is not what was expected

Question

#include
#include
#include
#include


__global__ void setVal(char **c){

c[(blockIdx.y * gridDim.x         


        

Answer 1

There are several problems I'm seeing here. Here are some of the most obvious ones:

First, my guess is that the character string constant "4" is stored in host (CPU) memory, so you would have to copy it explicitly to device (global) memory. Once the string "4" is in device memory, then you can store a pointer to "4" in a device memory value, such as an element of array arr.

Second, the array x you pass to the setValues kernel is also in host memory. Remember that you need to use cudaMalloc to allocate a (global) device memory region, which an on-device kernel can then point to.