The HelloWorldCuda thorn does not seem to work in my build of the Einstein Toolkit, ET_2024_11 release. The routine, HelloWorldCUDA_evol, that launches the cuda kernel uses cctk_lsh grid size values that are very large (x-dir > 1x10^9), which then tries to launch too many kernels. Below is the code:

extern "C"
void HelloWorldCUDA_evol(CCTK_ARGUMENTS)
{
DECLARE_CCTK_ARGUMENTS;

const int val1 = cctk_iteration;
const int val2 = 3;
int res = 42;                 // poison

const dim3 blockDim(4, 4, 4);

// const dim3 gridDim((cctk_lsh[0] + blockDim.x - 1) / blockDim.x, // Commented out by ALS
// (cctk_lsh[1] + blockDim.y - 1) / blockDim.y,
// (cctk_lsh[2] + blockDim.z - 1) / blockDim.z);

// This code does work - ALS
const dim3 gridDim((8 + blockDim.x - --

Ticket URL: https://bitbucket.org/einsteintoolkit/tickets/issues/2844/helloworldcuda