https://github.com/pytorch/pytorch/pull/164820 introduced a bug that `_StridedShard` will call parent class `Shard`'s `split_tensor` method, thus results in incorrect data locality. (I think @ezyang spotted this issue, but we have no test to capture this)
Meanwhile, I notice another bug that when we normalize a `_StridedShard`'s placement, it will also trigger parent class `Shard`'s `split_tensor` method because it will create a Shard class [here](0c14f55de6/torch/distributed/tensor/_api.py (L783)). I think we never test `distribute_tensor` for `_StridedShard` before. So I added a test here to compare against ordered shard.
Using classmethod because the _split_tensor logic is different between `Shard` and `_StridedShard`. Basically I want to shard on local tensors without initializing the Shard object:
```
local_tensor = _StridedShard._make_shard_tensor(dim, tensor, mesh, mesh_dim, split_factor=split_factor)
local_tensor = Shard._make_shard_tensor(dim, tensor, mesh, mesh_dim)
```
Pull Request resolved: https://github.com/pytorch/pytorch/pull/165533
Approved by: https://github.com/XilunWu
ab65498d71