[DTensor] Add test with parallelize_module (#2598)

Author: kshitij12345

thunder/dynamo/splitter.py

@@ -19,6 +19,7 @@
     checkpoint_converter,
     _get_example_inputs_from_placeholder,
     _ThunderSplitGraphModule,
+    translate_dtensor_ops,
 )
 
 if TYPE_CHECKING:
@@ -98,6 +99,7 @@ def forward(self, l_x_: "f32[2]", y: "f32[2]"):
     split_reasons: list[SplitReason] = []
 
     nodes_in_unsupported_ctx_regions = get_nodes_in_unsupported_ctx_regions(gm)
+    translate_dtensor_ops(gm)
 
     def callback(node) -> int:
         nonlocal prev_value, partition_cnt, split_reasons, supported_partitions
@@ -119,9 +121,14 @@ def callback(node) -> int:
             )
             split_reasons.append(split_reason)
         else:
-            is_thunder_supported, split_reason = is_node_supported_by_thunder(node)
-            if split_reason is not None:
-                split_reasons.append(split_reason)
+            # To support dynamo generated prims for `parallelize_module`.
+            # `translate_dtensor_ops` will mark the target as thunder supported if it is a DTensor operation.
+            if hasattr(node.target, "thunder_supported") and node.target.thunder_supported:
+                is_thunder_supported, split_reason = True, None
+            else:
+                is_thunder_supported, split_reason = is_node_supported_by_thunder(node)
+                if split_reason is not None:
+                    split_reasons.append(split_reason)
 
         if prev_value == is_thunder_supported:  # We are in the same region.
             return partition_cnt

thunder/dynamo/utils.py

@@ -1050,3 +1050,78 @@ def get_compiled_fn_and_timing(report, compile_fn, timer_fn):
         err_msg = ", ".join([f"{x.name} raised exception: {x.compiled_fn}" for x in sorted_compiled_gm_to_measurement])
         raise RuntimeError(f"No compiler was able to compile the graph module, {err_msg}")
     return sorted_compiled_gm_to_measurement[0].compiled_fn
+
+
+def translate_dtensor_ops(gm: torch.fx.GraphModule) -> None:
+    # We need this function because:
+    #
+    # For a program like:
+    # ```
+    # model = nn.Linear(hidden_size, hidden_size, bias=False)
+    # parallel_model = parallelize_module(model, mesh, {"fc1": ColwiseParallel()})
+    # model.fc1.weight.requires_grad = False
+
+    # # parallelize_module will handle the conversion to DTensor
+    # i = torch.randn(hidden_size, hidden_size)
+    # ````
+    #
+    # Dynamo captures an FX-Graph like:
+    # ```
+    # def forward(self, L_x_: "f32[16, 16]", L_self_modules_fc1_parameters_weight_: "f32[16, 16]"):
+    #         l_x_ = L_x_
+    #         l_self_modules_fc1_parameters_weight_ = L_self_modules_fc1_parameters_weight_
+    #
+    #         input_tensor: "f32[16, 16]" = torch__dynamo_variables_torch_prim_from_local(l_x_);  l_x_ = None
+    #
+    #         linear: "f32[16, 16]" = torch._C._nn.linear(input_tensor, l_self_modules_fc1_parameters_weight_, None);  input_tensor = l_self_modules_fc1_parameters_weight_ = None
+    #
+    #         outputs: "f32[16, 16]" = torch__dynamo_variables_tensor_prim_redistribute(linear);  linear = None
+    #
+    #         hook_result: "f32[16, 8]" = torch__dynamo_variables_tensor_prim_to_local(outputs);  outputs = None
+    #         return (hook_result,)
+    # ```
+    # where:
+    #      1. In the FX Graph, the Tensor Parallel computation is decomposed into primitive operations such as `torch__dynamo_variables_torch_prim_from_local`, `torch__dynamo_variables_tensor_prim_redistribute`, and others.
+    #      2. It is important to note that these decompositions actually capture (close over) values such as `placements` and other metadata.
+    #         For example, to understand the placements to which the output will be redistributed using `torch__dynamo_variables_tensor_prim_redistribute`,
+    #         we need to use `inspect.getclosurevars(node.target)` to examine the values (like placements) that are captured and used during execution.
+    #         The reference for where this closure is created can be found at:
+    #         https://github.com/pytorch/pytorch/blob/0ab075a69e4577a60c4dcbff7bcc2ecd0a15ce46/torch/_dynamo/variables/tensor.py#L1186-L1210
+
+    from thunder.torch.experimental.dtensor_torch_and_prims import (
+        dtensor_from_local_prim,
+        dtensor_redistribute_prim,
+        dtensor_to_local_prim,
+    )
+
+    for node in gm.graph.nodes:
+        try:
+            closure_vars = inspect.getclosurevars(node.target)
+
+            if "from_local" in node.target.__name__:
+                mesh = closure_vars.nonlocals["args_as_value"][0]
+                placements = closure_vars.nonlocals["args_as_value"][1]
+
+                def dtensor_from_local_prim_wrapper(x, mesh=mesh, placements=placements):
+                    return dtensor_from_local_prim(x, mesh, placements)
+
+                dtensor_from_local_prim_wrapper.thunder_supported = True
+                node.target = dtensor_from_local_prim_wrapper
+            if "redistribute" in node.target.__name__:
+                kwargs = closure_vars.nonlocals["kwargs_as_value"]
+                placements = kwargs["placements"]
+
+                def dtensor_redistribute_prim_wrapper(x, placements=placements):
+                    return dtensor_redistribute_prim(x, placements=placements)
+
+                dtensor_redistribute_prim_wrapper.thunder_supported = True
+                node.target = dtensor_redistribute_prim_wrapper
+            if "to_local" in node.target.__name__:
+
+                def dtensor_to_local_prim_wrapper(x):
+                    return dtensor_to_local_prim(x)
+
+                dtensor_to_local_prim_wrapper.thunder_supported = True
+                node.target = dtensor_to_local_prim_wrapper
+        except Exception:
+            pass

thunder/tests/distributed/test_dtensor.py

@@ -15,6 +15,10 @@
 from torch.distributed._tensor import DeviceMesh, distribute_tensor
 from torch.distributed.tensor.placement_types import Shard, Replicate
 from torch.testing._internal.distributed._tensor.common_dtensor import DTensorConverter
+from torch.distributed.tensor.parallel import (
+    parallelize_module,
+    ColwiseParallel,
+)
 
 from torch.testing._internal import common_utils
 
@@ -23,6 +27,7 @@
 from thunder.tests.utils import is_output_differentiable, filter_differentiable_outputs
 import thunder.core.dtypes as dtypes
 from thunder.core.pytree import tree_flatten
+from thunder.dynamo import thunderfx
 
 
 # NOTE: We run all these similar functions seperately
@@ -272,6 +277,43 @@ def fn(x):
 
         torch.testing.assert_close(actual, expected)
 
+    @common_utils.parametrize("jit_fn", (thunder.jit, thunderfx), name_fn=lambda jit_fn: jit_fn.__name__)
+    def test_dtensor_columnwise_parallel(self, jit_fn):
+        num_devices = self.world_size
+        mesh = DeviceMesh("cuda", list(range(num_devices)))
+        dim_size = 16
+        in_dtensor = torch.randn(dim_size, dim_size, requires_grad=False)
+        m = torch.nn.Linear(dim_size, dim_size)
+        m.requires_grad_(False)
+
+        parallelized_model = parallelize_module(m, mesh, ColwiseParallel())
+
+        # `parallelize_module` sets `requires_grad` to True, set it to False again.
+        parallelized_model.requires_grad_(False)
+
+        actual = parallelized_model(in_dtensor)
+        expected = m(in_dtensor)
+        torch.testing.assert_close(actual, expected)
+
+        tmodel = jit_fn(parallelized_model, nv_enable_linear=True)
+
+        if jit_fn == thunder.jit:
+            # Original error caught by the interpreter:
+            # File "/opt/pytorch/lightning-thunder/thunder/core/jit_ext.py", line 444, in _general_jit_getattr_lookaside
+            # obj.original_value.__dict__,
+            # ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+            # AttributeError: 'object' object has no attribute '__dict__'. Did you mean: '__dir__'?
+            with self.assertRaises(thunder.core.interpreter.InterpreterError):
+                actual = tmodel(in_dtensor)
+        else:
+            actual = tmodel(in_dtensor)
+            torch.testing.assert_close(actual, expected)
+
+        if jit_fn == thunderfx:
+            assert len(tmodel._backend.subgraph_infos) == 1
+            assert len(tmodel._backend.subgraph_infos[0].thunder_compiled_fns) == 1
+            assert len(tmodel._backend.subgraph_infos[0].split_reasons) == 0
+
     @common_utils.parametrize("executor", tuple(executors_map.keys()))
     @common_utils.parametrize(
         "input_shardings",

thunder/torch/experimental/dtensor_proxy.py

@@ -69,6 +69,41 @@ def placements(self):
     def device_mesh(self):
         return self.spec._o.device_mesh
 
+    @staticmethod
+    def from_local(
+        x,
+        mesh,
+        placements,
+        *,
+        run_check: bool = False,
+        shape: torch.Size | None = None,
+        stride: tuple[int, ...] | None = None,
+    ):
+        import thunder.torch.experimental.dtensor_torch_and_prims as dtensor_torch_and_prims
+
+        res = dtensor_torch_and_prims.dtensor_from_local_prim(
+            x, mesh, placements, run_check=run_check, shape=shape, stride=stride
+        )
+        return res
+
+    def redistribute(
+        self,
+        device_mesh: "Optional[DeviceMesh]" = None,
+        placements: "Optional[Sequence[Placement]]" = None,
+        *,
+        async_op: bool = False,
+    ) -> "DTensor":
+        import thunder.torch.experimental.dtensor_torch_and_prims as dtensor_torch_and_prims
+
+        res = dtensor_torch_and_prims.dtensor_redistribute_prim(self, device_mesh, placements, async_op=async_op)
+        return res
+
+    def to_local(self, *, grad_placements: "Optional[Sequence[Placement]]" = None):
+        import thunder.torch.experimental.dtensor_torch_and_prims as dtensor_torch_and_prims
+
+        res = dtensor_torch_and_prims.dtensor_to_local_prim(self, grad_placements=grad_placements)
+        return res
+
     def replace(self, **changes):
         r"""Return a copy of the TensorProxy object with new values for the specified fields as given to the constructor as arguments.
         Valid keyword arguments are ``name``, ``history``, ``shape``, ``dtype``, ``device``, ``requires_grad``, ``distparallel_type``,  ``thunder_fsdp_padding_size``.

thunder/torch/experimental/dtensor_torch_and_prims.py

@@ -1,6 +1,7 @@
 from functools import partial
 from collections.abc import Callable
 from enum import auto, Enum
+from collections.abc import Sequence
 from looseversion import LooseVersion
 
 from thunder.torch import torchsymbol, TensorLike, register_function
@@ -371,6 +372,100 @@ def dtensor_reciprocal(a: TensorLike) -> TensorLike:
     )
 
 
+if torch.distributed.is_available():
+    from torch.distributed.tensor import DTensor
+    from torch.distributed.tensor.placement_types import Placement, DeviceMesh
+
+    def dtensor_from_local_meta(
+        x,
+        mesh,
+        placements,
+        *,
+        run_check: bool = False,
+        shape: torch.Size | None = None,
+        stride: tuple[int, ...] | None = None,
+    ):
+        res = run_with_fake_tensor(
+            DTensor.from_local, x, mesh, placements, run_check=run_check, shape=shape, stride=stride
+        )
+        from thunder.torch.experimental.dtensor_proxy import proxify_dtensor
+
+        res = proxify_dtensor(res)
+        return res
+
+    dtensor_from_local_prim = make_prim("dtensor_from_local", "dtensor_from_local", meta=dtensor_from_local_meta)
+
+    dtensor_from_local_prim_impl = pytorchex.register_operator(
+        "dtensor_from_local", like=dtensor_from_local_prim, fn=DTensor.from_local
+    )
+
+    pytorchex.register_implementation(dtensor_from_local_prim, dtensor_from_local_prim_impl)
+
+    @dtensor_torchsymbol(DTensor.from_local, id="dtensor.torch.from_local")
+    def dtensor_from_local(
+        x,
+        mesh,
+        placements,
+        *,
+        run_check: bool = False,
+        shape: torch.Size | None = None,
+        stride: tuple[int, ...] | None = None,
+    ) -> DTensorProxy | None:
+        return dtensor_from_local_prim(x, mesh, placements, run_check=run_check, shape=shape, stride=stride)
+
+    def dtensor_redistribute_meta(
+        dtensor,
+        device_mesh: DeviceMesh | None = None,
+        placements: Sequence[Placement] | None = None,
+        *,
+        async_op: bool = False,
+    ) -> DTensorProxy | None:
+        res = run_with_fake_tensor(DTensor.redistribute, dtensor, device_mesh, placements, async_op=async_op)
+        from thunder.torch.experimental.dtensor_proxy import proxify_dtensor
+
+        res = proxify_dtensor(res)
+        return res
+
+    dtensor_redistribute_prim = make_prim(
+        "dtensor_redistribute", "dtensor_redistribute", meta=dtensor_redistribute_meta
+    )
+
+    dtensor_redistribute_prim_impl = pytorchex.register_operator(
+        "dtensor_redistribute", like=dtensor_redistribute_prim, fn=DTensor.redistribute
+    )
+
+    @dtensor_torchsymbol(DTensor.redistribute, id="dtensor.torch.redistribute")
+    def dtensor_redistribute(
+        dtensor,
+        device_mesh: DeviceMesh | None = None,
+        placements: Sequence[Placement] | None = None,
+        *,
+        async_op: bool = False,
+    ) -> DTensorProxy | None:
+        return dtensor_redistribute_prim(dtensor, device_mesh, placements, async_op=async_op)
+
+    pytorchex.register_implementation(dtensor_redistribute_prim, dtensor_redistribute_prim_impl)
+
+    def dtensor_to_local_meta(dtensor, *, grad_placements: Sequence[Placement] | None = None):
+        res = run_with_fake_tensor(DTensor.to_local, dtensor, grad_placements=grad_placements)
+        from thunder.core.proxies import proxy
+
+        res = proxy(res)
+        return res
+
+    dtensor_to_local_prim = make_prim("dtensor_to_local", "dtensor_to_local", meta=dtensor_to_local_meta)
+
+    dtensor_to_local_prim_impl = pytorchex.register_operator(
+        "dtensor_to_local", like=dtensor_to_local_prim, fn=DTensor.to_local
+    )
+
+    pytorchex.register_implementation(dtensor_to_local_prim, dtensor_to_local_prim_impl)
+
+    @dtensor_torchsymbol(DTensor.to_local, id="dtensor.torch.to_local")
+    def dtensor_to_local(dtensor, *, grad_placements: Sequence[Placement] | None = None) -> DTensorProxy | None:
+        return dtensor_to_local_prim(dtensor, grad_placements=grad_placements)
+
+
 expand = partial(expand_impl, broadcast_prim=dtensor_broadcast_in_dim_prim)
 maybe_broadcast = partial(maybe_broadcast_impl, expand_fn=expand)