Use non-variable stride per rank path for dynamo (#2018)

Summary:
Pull Request resolved: #2018

Pick non-variable stride per rank path for dynamo for now.
In future that will be solved with first batch path memorizaiton.

Reviewed By: gnahzg

Differential Revision: D57562279

fbshipit-source-id: 73bb55580875f0b11e2daf477d82a21fdd90220e

Author: Ivan Kobzarev

torchrec/distributed/dist_data.py

@@ -192,9 +192,13 @@ def _get_recat_tensor_compute(
             + (feature_order.expand(LS, FO_S0) * LS)
         ).reshape(-1)
 
-        vb_condition = batch_size_per_rank is not None and any(
-            bs != batch_size_per_rank[0] for bs in batch_size_per_rank
-        )
+        # Use non variable stride per rank path for dynamo
+        # TODO(ivankobzarev): Implement memorization of the path from the first batch.
+        vb_condition = False
+        if not is_torchdynamo_compiling():
+            vb_condition = batch_size_per_rank is not None and any(
+                bs != batch_size_per_rank[0] for bs in batch_size_per_rank
+            )
 
         if vb_condition:
             batch_size_per_rank_tensor = torch._refs.tensor(