A warning appears in DDP using ConvNeXt

[Toshimasa-Matsumoto]

When I start training using DDP with ConvNeXt, the following warning appears.

What caused the warning?
Also, is there a way to avoid the warning?

UserWarning: Grad strides do not match bucket view strides. This may indicate grad was not created according to the gradient layout contract, or that the param's strides changed since DDP was constructed.  This is not an error, but may impair performance.
grad.sizes() = [1024, 1, 7, 7], strides() = [49, 1, 7, 1]
bucket_view.sizes() = [1024, 1, 7, 7], strides() = [49, 49, 7, 1] (Triggered internally at ../torch/csrc/distributed/c10d/reducer.cpp:323.)
  Variable._execution_engine.run_backward(  # Calls into the C++ engine to run the backward pass

Thank you.

[anhtienng]

I also got this warning.
I found this https://github.com/pytorch/pytorch/issues/47163. So the rule is you need add .contiguous() after the permute operation