How to use Pinned Memory for ROS Node

I have a network running within a ROS node. It produces a large tensor, which I have to copy to CPU and send it to another node

# Called once
pinned_tensor = torch.zeros((1,128,512,512)).pin_memory()

# Called in Loop
pinned_tensor[:] =

This is still slow even if i use pin memory. Am i using it incorrectly?