CUDA: Using realloc inside kernel

Question

I know that it is possible to use malloc inside the kernel to allocate memory on GPU's global memory. Is it also possible to use realloc?

Answer 1

You could write you own realloc device function for your data type.

Just allocate the new space for a new array, copy the old values to the new, free the old array space, return the new with more space.

Approximately like the following code fragment:

__device__ MY_TYPE* myrealloc(int oldsize, int newsize, MY_TYPE* old)
{
    MY_TYPE* newT = (MY_TYPE*) malloc (newsize*sizeof(MY_TYPE));

    int i;

    for(i=0; i<oldsize; i++)
    {
        newT[i] = old[i];
    }

    free(old);
    return newT;
}

But be sure to call it, if you really need it. Also add proper error checking.

Answer 2

In the Cuda Programming Guide, when they introduce malloc and free functions, there is no mention of realloc. I would assume that it does not exist.

If you want to know it for sure, why don't you write a simple kernel and try using it?