Let’s say you build PyTorch with NNPACK. Now, when doing inference on an ARM CPU, how do you tell PyTorch whether to use THNN or NNPACK for tensor computations?
And, to head off some likely questions:

Yes, I am using PyTorch on an ARM device; no, it’s not a smartphone
yes, I know I can also use Caffe2 on ARM devices; no my model isn’t currently compatible with onnx or caffe2