fix: Remove pytorch overhead while finding fusions for fully convertible models (#3311)

Author: peri044

py/torch_tensorrt/dynamo/_compiler.py

@@ -765,7 +765,9 @@ def contains_metadata(gm: torch.fx.GraphModule) -> bool:
                 min_block_size=settings.min_block_size,
                 torch_executed_ops=settings.torch_executed_ops,
                 require_full_compilation=settings.require_full_compilation,
+                skip_fusion=(num_supported_ops == total_ops),
             )
+
         except torch.fx.passes.splitter_base.FxNetSplitterInternalError:
             logger.error(
                 "Partitioning failed on the subgraph with fast partition. See trace above. "

py/torch_tensorrt/dynamo/partitioning/_adjacency_partitioner.py

@@ -111,6 +111,7 @@ def __init__(
         min_block_size: int = MIN_BLOCK_SIZE,
         require_full_compilation: bool = REQUIRE_FULL_COMPILATION,
         return_tuple: bool = False,
+        skip_fusion: bool = False,
     ):
         """
         Preprocesses graph before splitting:
@@ -127,6 +128,7 @@ def __init__(
         self.settings = _SplitterSettingBase(
             min_acc_module_size=min_block_size,
             allow_non_tensor=True,
+            skip_fusion=skip_fusion,
         )
         self.operator_support = operator_support
 
@@ -252,6 +254,7 @@ def partition(
     min_block_size: int = MIN_BLOCK_SIZE,
     torch_executed_ops: Collection[Target] = set(),
     require_full_compilation: bool = REQUIRE_FULL_COMPILATION,
+    skip_fusion: bool = False,
 ) -> Tuple[torch.fx.GraphModule, OpSupportTester]:
     """Partition an FX GraphModule with aten ops into TRT engines
     Partitioning is based on converter operator support
@@ -262,6 +265,7 @@ def partition(
         min_block_size: Minimum number of operators per TRT-Engine Block
         torch_executed_ops: Collection of operations to run in Torch, regardless of converter coverage
         require_full_compilation: Require that all computational operators be run in TRT
+        skip_fusion: Skip fusions found by FxNetAccFusionsFinder
     Returns:
         torch.fx.GraphModule, OpSupportTester
     """
@@ -277,6 +281,7 @@ def partition(
         supported_ops,
         min_block_size=min_block_size,
         require_full_compilation=require_full_compilation,
+        skip_fusion=skip_fusion,
     )
 
     partitioned_graph = partitioner.partition_graph()