Revert "Graph break with error message (#158800)"

This reverts commit cae4746952afbb6d26ecf7599cb7c6c449c69ef4.

Reverted https://github.com/pytorch/pytorch/pull/158800 on behalf of https://github.com/clee2000 due to broke some tests on main inductor/test_distributed_patterns.py::DistributedPatternTests::test_nn_param_return4 [GH job link](https://github.com/pytorch/pytorch/actions/runs/16507837934/job/46685704688) [HUD commit link](cae4746952), note to self: bad TD, but also dynamo/test_repros failed but didn't get skipped by TD so maybe a landrace, or I just blaming the wrong commit entirely.. ([comment](https://github.com/pytorch/pytorch/pull/158800#issuecomment-3115224608))

test/dynamo/test_aot_autograd.py

@@ -1339,7 +1339,6 @@ SeqNr|OrigAten|SrcFn|FwdSrcFn
         FileCheck().check("bw_donated_idxs=[1]").run("\n".join(captured.output))
 
     @torch._functorch.config.patch("donated_buffer", True)
-    @torch._dynamo.config.patch("graph_break_on_nn_param_ctor", False)
     def test_donated_buffer6(self):
         if is_dynamic_shape_test(self._testMethodName):
             # parameters should not be dynamic shape

test/dynamo/test_repros.py

@@ -42,7 +42,6 @@ import torch.distributed as dist
 import torch.library
 import torch.utils._pytree as pytree
 from torch import nn
-from torch._dynamo.backends.debugging import ExplainWithBackend
 from torch._dynamo.debug_utils import same_two_models
 from torch._dynamo.testing import (
     CompileCounter,
@@ -7135,28 +7134,6 @@ def forward(self, s77 : torch.SymInt, s27 : torch.SymInt, L_x_ : torch.Tensor):
         torch.compile(f, backend="eager", fullgraph=True)(eye, out_res)
         self.assertEqual(out_ref, out_res)
 
-    def test_nn_parameter_ctor_graph_breaks(self):
-        def fn():
-            param = torch.nn.Parameter(torch.ones(10))
-            return param * 2
-
-        self.maxDiff = None
-        eb = ExplainWithBackend("eager")
-        optimized_fn = torch.compile(fn, backend=eb)
-        _ = optimized_fn()
-        explain_output = eb.output()
-        self.assertEqual(explain_output.graph_break_count, 1)
-        expected_msg = (
-            "Attempted to use `torch.nn.Parameter()` constructor with Dynamo\n"
-            "  Explanation: Dynamo does not support this\n"
-            "  Hint: Try to construct `torch.nn.Parameter()` outside the compiled region.\n"
-            "  Hint: If this is not possible, turn `graph_break_on_nn_param_ctor` off\n"
-            "  Hint: It may be possible to write Dynamo tracing rules for this code. "
-            "Please report an issue to PyTorch if you encounter this graph break often and it is causing performance issues.\n\n"
-            "  Developer debug context: \n"
-        )
-        self.assertEqual(explain_output.break_reasons[0].reason, expected_msg)
-
 
 class ReproTestsDevice(torch._dynamo.test_case.TestCase):
     def test_sub_alpha_scalar_repro(self, device):

torch/_dynamo/config.py

@@ -562,13 +562,6 @@ caching_precompile = os.environ.get("TORCH_CACHING_PRECOMPILE", "0") == "1"
 # registering backward hooks on tensors contained within the compiled region.
 compiled_autograd = False
 
-
-# Checks if we should graph break when seeing nn parameter constructors
-# in dynamo; this is so that we clearly fail and ask users to move outside
-# the function as opposed to trying to support the ctor with unclear semantics
-# See https://github.com/pytorch/pytorch/issues/157452 for more context
-graph_break_on_nn_param_ctor = True
-
 # Overrides torch.compile() kwargs for Compiled Autograd:
 compiled_autograd_kwargs_override: dict[str, Any] = {}
 

torch/_dynamo/graph_break_registry.json

@@ -2509,20 +2509,5 @@
         "It may be possible to write Dynamo tracing rules for this code. Please report an issue to PyTorch if you encounter this graph break often and it is causing performance issues."
       ]
     }
-  ],
-  "GB0252": [
-    {
-      "Gb_type": "Attempted to use `torch.nn.Parameter()` constructor with Dynamo",
-      "Context": "",
-      "Explanation": "Dynamo does not support this",
-      "Hints": [
-        "Try to construct `torch.nn.Parameter()` outside the compiled region.",
-        "If this is not possible, turn `graph_break_on_nn_param_ctor` off",
-        "It may be possible to write Dynamo tracing rules for this code. Please report an issue to PyTorch if you encounter this graph break often and it is causing performance issues."
-      ],
-      "Additional_Info": [
-        "Try to construct nn.Parameter() outside the compiled region.  If this is not possible, turn `graph_break_on_nn_param_ctor` off"
-      ]
-    }
   ]
 }

torch/_dynamo/variables/torch.py

@@ -1696,20 +1696,6 @@ For now, dynamo will explicitly graph break when it encounters user code with th
         if data.source:
             return cls._nn_param_via_prefix_insert(tx, data, requires_grad)
 
-        if config.graph_break_on_nn_param_ctor:
-            # Need user to manually move since we cannot
-            unimplemented_v2(
-                gb_type="Attempted to use `torch.nn.Parameter()` constructor with Dynamo",
-                context="",
-                explanation="Dynamo does not support this",
-                hints=[
-                    "Try to construct `torch.nn.Parameter()` outside the compiled region.",
-                    "If this is not possible, turn `graph_break_on_nn_param_ctor` off",
-                    *graph_break_hints.SUPPORTABLE,
-                ],
-            )
-
-        # TODO[@lucaskabela]: Remove the behavior below since it is deprecated
         if isinstance(
             data, TensorWithTFOverrideVariable
         ) or is_traceable_wrapper_subclass_type(data.class_type):