fix ZCH inference input dist error (#2682)

Summary:
Pull Request resolved: #2682

Serving test failed when ZCH sharding is enabled because embedding lookup request Out of Bound.

After compared with training sharding input_dist, found that the keep_orig_idx flag is True when calling training block bucketize kernel, but not set in inference. So this diff is to make that consistent between training and inference, so the ID distribution works the same between training and inference.

Reviewed By: kausv

Differential Revision: D68123290

fbshipit-source-id: 57813e55fc946dec79a522cfb341974a2ed7669d

torchrec/distributed/embedding_sharding.py

@@ -132,6 +132,7 @@ def _fx_wrap_seq_block_bucketize_sparse_features_inference(
     bucketize_pos: bool = False,
     block_bucketize_pos: Optional[List[torch.Tensor]] = None,
     total_num_blocks: Optional[torch.Tensor] = None,
+    keep_original_indices: bool = False,
 ) -> Tuple[
     torch.Tensor,
     torch.Tensor,
@@ -159,6 +160,7 @@ def _fx_wrap_seq_block_bucketize_sparse_features_inference(
         max_B=_fx_wrap_max_B(kjt),
         block_bucketize_pos=block_bucketize_pos,
         return_bucket_mapping=True,
+        keep_orig_idx=keep_original_indices,
     )
 
     return (
@@ -305,6 +307,7 @@ def bucketize_kjt_inference(
     bucketize_pos: bool = False,
     block_bucketize_row_pos: Optional[List[torch.Tensor]] = None,
     is_sequence: bool = False,
+    keep_original_indices: bool = False,
 ) -> Tuple[KeyedJaggedTensor, Optional[torch.Tensor], Optional[torch.Tensor]]:
     """
     Bucketizes the `values` in KeyedJaggedTensor into `num_buckets` buckets,
@@ -352,6 +355,7 @@ def bucketize_kjt_inference(
             total_num_blocks=total_num_buckets_new_type,
             bucketize_pos=bucketize_pos,
             block_bucketize_pos=block_bucketize_row_pos,
+            keep_original_indices=keep_original_indices,
         )
     else:
         (

torchrec/distributed/mc_modules.py

@@ -1171,6 +1171,7 @@ def _create_input_dists(
                 has_feature_processor=sharding._has_feature_processor,
                 need_pos=False,
                 embedding_shard_metadata=emb_sharding,
+                keep_original_indices=True,
             )
             self._input_dists.append(input_dist)
 

torchrec/distributed/sharding/rw_sharding.py

@@ -649,10 +649,12 @@ def __init__(
         has_feature_processor: bool = False,
         need_pos: bool = False,
         embedding_shard_metadata: Optional[List[List[int]]] = None,
+        keep_original_indices: bool = False,
     ) -> None:
         super().__init__()
         logger.info(
             f"InferRwSparseFeaturesDist: {world_size=}, {num_features=}, {feature_hash_sizes=}, {feature_total_num_buckets=}, {device=}, {is_sequence=}, {has_feature_processor=}, {need_pos=}, {embedding_shard_metadata=}"
+            f", keep_original_indices={keep_original_indices}"
         )
         self._world_size: int = world_size
         self._num_features = num_features
@@ -683,6 +685,7 @@ def __init__(
         self._embedding_shard_metadata: Optional[List[List[int]]] = (
             embedding_shard_metadata
         )
+        self._keep_original_indices = keep_original_indices
 
     def forward(self, sparse_features: KeyedJaggedTensor) -> InputDistOutputs:
         block_sizes, block_bucketize_row_pos = get_block_sizes_runtime_device(
@@ -717,6 +720,7 @@ def forward(self, sparse_features: KeyedJaggedTensor) -> InputDistOutputs:
                 block_bucketize_row_pos
             ),
             is_sequence=self._is_sequence,
+            keep_original_indices=self._keep_original_indices,
         )
         # KJTOneToAll
         dist_kjt = self._dist.forward(bucketized_features)