modify unflatten for vllm (#3297)

Author: liangel-02

test/prototype/safetensors/test_safetensors_support.py

@@ -74,9 +74,10 @@ def test_safetensors(self, config, act_pre_scale=False):
 
             save_file(tensors_data_dict, f.name, metadata=metadata)
             tensors_data_dict, metadata = load_data(file_path=f.name, device="cuda")
-            reconstructed_dict = unflatten_tensor_state_dict(
+            reconstructed_dict, leftover_tensor_data_dict = unflatten_tensor_state_dict(
                 tensors_data_dict, metadata
             )
+            assert not leftover_tensor_data_dict
 
         model = torch.nn.Sequential(
             torch.nn.Linear(128, 256, dtype=torch.bfloat16, device="cuda")
@@ -85,6 +86,47 @@ def test_safetensors(self, config, act_pre_scale=False):
         output = model(*example_inputs)
         assert torch.equal(output, ref_output)
 
+    @parametrize(
+        "config, act_pre_scale",
+        [
+            (Float8DynamicActivationFloat8WeightConfig(granularity=PerRow()), False),
+            (Int4WeightOnlyConfig(), False),
+            (Int4WeightOnlyConfig(), True),
+            (Int4WeightOnlyConfig(int4_packing_format="tile_packed_to_4d"), False),
+            (IntxWeightOnlyConfig(), False),
+            (Int8DynamicActivationIntxWeightConfig(), False),
+        ],
+    )
+    def test_safetensors_sharded(self, config, act_pre_scale=False):
+        model = torch.nn.Sequential(
+            torch.nn.Linear(128, 256, dtype=torch.bfloat16, device="cuda")
+        )
+        quantize_(model, config)
+        if act_pre_scale:
+            model[0].weight.act_pre_scale = torch.ones(
+                (1), dtype=torch.bfloat16, device="cuda"
+            )
+
+        with tempfile.NamedTemporaryFile() as f:
+            tensors_data_dict, metadata = flatten_tensor_state_dict(model.state_dict())
+            save_file(tensors_data_dict, f.name, metadata=metadata)
+            tensors_data_dict, metadata = load_data(file_path=f.name, device="cuda")
+
+            # simulate missing info on future file
+            if act_pre_scale:
+                del tensors_data_dict["0._weight_act_pre_scale"]  # optional tensor data
+            else:
+                del tensors_data_dict["0._weight_qdata"]
+
+            reconstructed_dict, leftover_tensor_data_dict = unflatten_tensor_state_dict(
+                tensors_data_dict, metadata
+            )
+
+            # since qdata is missing, layer 0 should not have been processed
+            for key in tensors_data_dict.keys():
+                if key.startswith("0._weight_"):
+                    assert key in leftover_tensor_data_dict
+
 
 instantiate_parametrized_tests(TestSafeTensors)
 

torchao/prototype/safetensors/safetensors_support.py

@@ -34,7 +34,8 @@ def unflatten_tensor_state_dict(
             '_data': {
                 'block_size': [1,32],
                 ...
-            }
+            },
+            '_tensor_data_names': ['qdata', 'scale']
         }
         '0.bias': {
             '_type': 'torch.Tensor',
@@ -66,33 +67,51 @@ def unflatten_tensor_state_dict(
 
     tensor_names = json.loads(metadata["tensor_names"])
     result = {}
-
+    leftover_state_dict = tensors_data_dict.copy()
     for tensor_name in tensor_names:
+        processed_tensors = []
+
         module_fqn, weight_name = tensor_name.rsplit(".", 1)
 
         prefix = f"{module_fqn}._{weight_name}_"
         tensor_tensors = {}
+
         for key, value in combined_data.items():
             if key.startswith(prefix):
                 # Remove the prefix
                 tensor_tensors[key[len(prefix) :]] = value
 
         tensor_metadata = json.loads(metadata.get(tensor_name))
         tensor_type = tensor_metadata.get("_type")
+        complete_tensor_data_names = tensor_metadata.get("_tensor_data_names")
 
         if tensor_type in ALLOWED_TENSORS_SUBCLASSES:
-            if not tensor_tensors:
-                # we allow the option of loading in state_dict info for a single tensor
-                # if tensor state dict info is not loaded in yet, we wait for it to be provided
-                # in a future call
+            # if not all tensor data is present (ie missing qdata) we wait for it
+            # to be loaded in from a future call
+            if not len(tensor_tensors) is len(complete_tensor_data_names):
                 continue
             tensor_metadata["_data"].update(tensor_tensors)
             result[tensor_name] = object_from_dict(tensor_metadata)
+
+            for suffix in complete_tensor_data_names:
+                processed_tensors.append(prefix + suffix)
         elif tensor_type == torch.Tensor.__name__:
+            # we allow the option of loading in state_dict info for a single tensor
+            # if tensor state dict info is not loaded in yet, we wait for it to be provided
+            # in a future call
+            if tensor_name not in tensors_data_dict.keys():
+                continue
             result[tensor_name] = tensors_data_dict[tensor_name]
+            processed_tensors.append(
+                tensor_name
+            )  # add here because key for torch.Tensor has no prefix
         else:
             raise ValueError(f"Unsupported tensor type: {tensor_type}")
-    return result
+
+        for tensor_name in processed_tensors:
+            del leftover_state_dict[tensor_name]
+
+    return result, leftover_state_dict
 
 
 def flatten_tensor_state_dict(
@@ -125,7 +144,8 @@ def flatten_tensor_state_dict(
             '_data': {
                 'block_size': [1,32],
                 ...
-            }
+            },
+            '_tensor_data_names': ['qdata', 'scale']
         }
         '0.bias': {
             '_type': 'torch.Tensor',

torchao/prototype/safetensors/safetensors_utils.py

@@ -60,7 +60,23 @@ def default(self, o):
                 encoded_attribute = self.encode_value(attribute)
                 tensor_attr_dict[tensor_attribute_name] = encoded_attribute
 
-            return {"_type": o.__class__.__name__, "_data": tensor_attr_dict}
+            optional_tensor_data_names = (
+                o.optional_tensor_data_names
+                if hasattr(o, "optional_tensor_data_names")
+                else []
+            )
+            all_tensor_data_names = optional_tensor_data_names + o.tensor_data_names
+
+            _tensor_data_names = []
+            for tensor_data_name in all_tensor_data_names:
+                if getattr(o, tensor_data_name) is not None:
+                    _tensor_data_names.append(tensor_data_name)
+
+            return {
+                "_type": o.__class__.__name__,
+                "_data": tensor_attr_dict,
+                "_tensor_data_names": _tensor_data_names,
+            }
 
         if hasattr(o, "_fields") and hasattr(
             o, "_asdict"