Passing an struct including a pointer to another struct, to kernel in CUDA

Question

I have two structs as

struct collapsed {
    char **seq;
    int num;
};


struct data {
    collapsed *x;
    int num;
    int numblocks;
    int *blocksize         


        

Answer 1

You're dereferencing a host pointer on the device. X is a valid device pointer.

But when you copied the X struct to the device, you copied x along with it, which contains a host pointer. When you dereference that pointer:

collapsed x = X->x[0];
                 ^ this is dereferencing the x pointer

the device code throws an error.

More detail is given here as well as instructions on how to fix it.