Libtorch: How to make a Tensor with GPU pointer?

Question

Below is the pseudo-code of what I want to do. I already know how to move tensor to GPU (.cuda())...
But have no idea about using a GPU pointer to make a new tensor. Is there any method I've missed?
I don't want to copy devPtr back to the host side but just make the GPU tensor with the pointer.

int main(void) {
  float* devPtr;
  cudaMalloc((void**)&devPtr, sizeof(float)*HOSTDATA_SIZE);
  cudaMemcpy(devPtr, hostData, sizeof(float)*HOSTDATA_SIZE, cudaMemcpyHostToDevice);

  torch::Tensor inA = /* make Tensor with devPtr which is already in GPU */;
  torch::Tensor inB = torch::randn({1, 10, 512, 512}).cuda();

  torch::Tensor out = torch::matmul(inA, inB);

  std::cout << out << std::endl;
  return 0;
}

Answer 1

I think this should work, can you confirm ?

auto dims = torch::IntArrayRef{1, 10, 512, 512};
auto gpu_tensor = torch::from_blob(dev_ptr, dims, torch::TensorOptions().device(torch::kCUDA))

Be careful, torch::from_blob does not take ownership of the pointer.If you need to make gpu_tensor independant of the lifetime of dev_ptr, then you need to clone it.