Check zch config compability for transfer

torchrec/distributed/mc_modules.py

@@ -827,6 +827,7 @@ def sharded_parameter_names(self, prefix: str = "") -> Iterator[str]:
                     "_output_segments_tensor",
                     "_current_iter_tensor",
                     "_scalar_logger._scalar_logger_steps",
+                    "_hash_zch_bucket",
                 ]:
                     continue
                 if name in module._non_persistent_buffers_set:

torchrec/modules/hash_mc_modules.py

@@ -305,6 +305,7 @@ def __init__(
 
         self._max_probe = max_probe
         self._buckets = total_num_buckets
+        self.register_buffer("_hash_zch_bucket", torch.tensor(total_num_buckets))
         # Do not need to store in buffer since this is created and consumed
         # at each step https://fburl.com/code/axzimmbx
         self._evicted_indices = []