Change functional surgery method return values to None (#1543)

Some functional surgery methods previously returned the model object.

.ci/release_tests/example_1.py

@@ -4,7 +4,7 @@
 my_model = models.resnet18()
 
 # add blurpool and squeeze excite layers
-my_model = cf.apply_blurpool(my_model)
-my_model = cf.apply_squeeze_excite(my_model)
+cf.apply_blurpool(my_model)
+cf.apply_squeeze_excite(my_model)
 
 # your own training code starts here

README.md

@@ -112,8 +112,8 @@ from torchvision import models
 my_model = models.resnet18()
 
 # add blurpool and squeeze excite layers
-my_model = cf.apply_blurpool(my_model)
-my_model = cf.apply_squeeze_excite(my_model)
+cf.apply_blurpool(my_model)
+cf.apply_squeeze_excite(my_model)
 
 # your own training code starts here
 ```

composer/algorithms/blurpool/blurpool.py

@@ -26,7 +26,7 @@ def apply_blurpool(model: torch.nn.Module,
                    replace_maxpools: bool = True,
                    blur_first: bool = True,
                    min_channels: int = 16,
-                   optimizers: Optional[Union[Optimizer, Sequence[Optimizer]]] = None) -> torch.nn.Module:
+                   optimizers: Optional[Union[Optimizer, Sequence[Optimizer]]] = None) -> None:
     """Add anti-aliasing filters to strided :class:`torch.nn.Conv2d` and/or :class:`torch.nn.MaxPool2d` modules.
 
     These filters increase invariance to small spatial shifts in the input
@@ -55,9 +55,6 @@ def apply_blurpool(model: torch.nn.Module,
             then it is safe to omit this parameter. These optimizers will see
             the correct model parameters.
 
-    Returns:
-        The modified model
-
     Example:
         .. testcode::
 
@@ -78,8 +75,6 @@ def apply_blurpool(model: torch.nn.Module,
     module_surgery.replace_module_classes(model, optimizers=optimizers, policies=transforms)
     _log_surgery_result(model)
 
-    return model
-
 
 class BlurPool(Algorithm):
     """`BlurPool <http://proceedings.mlr.press/v97/zhang19a.html>`_ adds anti-aliasing filters to convolutional layers.

composer/algorithms/ema/ema.py

@@ -21,7 +21,7 @@
 __all__ = ['EMA', 'compute_ema']
 
 
-def compute_ema(model: torch.nn.Module, ema_model: torch.nn.Module, smoothing: float = 0.99):
+def compute_ema(model: torch.nn.Module, ema_model: torch.nn.Module, smoothing: float = 0.99) -> None:
     r"""Updates the weights of ``ema_model`` to be closer to the weights of ``model``
     according to an exponential weighted average. Weights are updated according to
 

composer/algorithms/factorize/factorize.py

@@ -28,7 +28,7 @@ def apply_factorization(model: torch.nn.Module,
                         latent_channels: Union[int, float] = 0.25,
                         min_features: int = 512,
                         latent_features: Union[int, float] = 0.25,
-                        optimizers: Optional[Union[Optimizer, Sequence[Optimizer]]] = None) -> torch.nn.Module:
+                        optimizers: Optional[Union[Optimizer, Sequence[Optimizer]]] = None) -> None:
     """Replaces :class:`torch.nn.Linear` and :class:`torch.nn.Conv2d` modules with
     :class:`.FactorizedLinear` and :class:`.FactorizedConv2d` modules.
 
@@ -71,9 +71,6 @@ def apply_factorization(model: torch.nn.Module,
             then it is safe to omit this parameter. These optimizers will see
             the correct model parameters.
 
-    Returns:
-        The modified model
-
     Example:
         .. testcode::
 
@@ -92,7 +89,6 @@ def apply_factorization(model: torch.nn.Module,
                                   min_features=min_features,
                                   latent_features=latent_features,
                                   optimizers=optimizers)
-    return model
 
 
 class Factorize(Algorithm):

composer/algorithms/gated_linear_units/gated_linear_units.py

@@ -96,7 +96,6 @@ def apply_gated_linear_units(model: torch.nn.Module,
                 NoEffectWarning('No instances of BertIntermediate were found so Gated Linear Units will be skipped '
                                 'as no modules can be replaced. This is likely because Gated Linear Units has already '
                                 'been applied to this model.'))
-            return
 
         # get the activation functions used
         act_fns = {module.intermediate_act_fn for module in intermediate_modules}

composer/algorithms/ghost_batchnorm/ghost_batchnorm.py

@@ -19,7 +19,7 @@
 
 def apply_ghost_batchnorm(model: torch.nn.Module,
                           ghost_batch_size: int = 32,
-                          optimizers: Optional[Union[Optimizer, Sequence[Optimizer]]] = None) -> torch.nn.Module:
+                          optimizers: Optional[Union[Optimizer, Sequence[Optimizer]]] = None) -> None:
     """Replace batch normalization modules with ghost batch normalization modules.
 
     Ghost batch normalization modules split their input into chunks of
@@ -39,7 +39,7 @@ def apply_ghost_batchnorm(model: torch.nn.Module,
             model parameters.
 
     Returns:
-        The modified model
+        The number of modules modified.
 
     Example:
         .. testcode::
@@ -59,7 +59,6 @@ def maybe_replace(module: torch.nn.Module, module_index: int) -> Optional[torch.
     # now checks if `module.__class__ == cls`, rather than `isinstance(module, cls)`
     transforms = {cls: maybe_replace for cls in [torch.nn.BatchNorm1d, torch.nn.BatchNorm2d, torch.nn.BatchNorm3d]}
     module_surgery.replace_module_classes(model, optimizers=optimizers, policies=transforms)
-    return model
 
 
 class GhostBatchNorm(Algorithm):

composer/algorithms/low_precision_layernorm/low_precision_layernorm.py

@@ -103,8 +103,6 @@ def apply_low_precision_layernorm(model, optimizers: Union[torch.optim.Optimizer
         warnings.warn(NoEffectWarning('No instances of torch.nn.LayerNorm found.'))
     log.info(f'Successfully replaced {len(replaced_instances)} instances of LayerNorm with LowPrecisionLayerNorm')
 
-    return model
-
 
 class LowPrecisionLayerNorm(Algorithm):
     """

composer/algorithms/squeeze_excite/squeeze_excite.py

@@ -21,7 +21,7 @@ def apply_squeeze_excite(
     latent_channels: float = 64,
     min_channels: int = 128,
     optimizers: Optional[Union[Optimizer, Sequence[Optimizer]]] = None,
-):
+) -> None:
     """Adds Squeeze-and-Excitation blocks (`Hu et al, 2019 <https://arxiv.org/abs/1709.01507>`_) after
     :class:`torch.nn.Conv2d` layers.
 
@@ -50,9 +50,6 @@ def apply_squeeze_excite(
             then it is safe to omit this parameter. These optimizers will see the correct
             model parameters.
 
-    Returns:
-        The modified model
-
     Example:
         .. testcode::
 
@@ -73,8 +70,6 @@ def convert_module(module: torch.nn.Module, module_index: int):
 
     module_surgery.replace_module_classes(model, optimizers=optimizers, policies={torch.nn.Conv2d: convert_module})
 
-    return model
-
 
 class SqueezeExcite2d(torch.nn.Module):
     """Squeeze-and-Excitation block from (`Hu et al, 2019 <https://arxiv.org/abs/1709.01507>`_)
@@ -164,10 +159,10 @@ def match(self, event: Event, state: State) -> bool:
         return event == Event.INIT
 
     def apply(self, event: Event, state: State, logger: Logger) -> Optional[int]:
-        state.model = apply_squeeze_excite(state.model,
-                                           optimizers=state.optimizers,
-                                           latent_channels=self.latent_channels,
-                                           min_channels=self.min_channels)
+        apply_squeeze_excite(state.model,
+                             optimizers=state.optimizers,
+                             latent_channels=self.latent_channels,
+                             min_channels=self.min_channels)
         layer_count = module_surgery.count_module_instances(state.model, SqueezeExciteConv2d)
 
         log.info(f'Applied SqueezeExcite to model {state.model.__class__.__name__} '

composer/algorithms/stochastic_depth/stochastic_depth.py

@@ -33,7 +33,7 @@ def apply_stochastic_depth(model: torch.nn.Module,
                            target_layer_name: str,
                            stochastic_method: str = 'block',
                            drop_rate: float = 0.2,
-                           drop_distribution: str = 'linear') -> torch.nn.Module:
+                           drop_distribution: str = 'linear') -> None:
     """Applies Stochastic Depth (`Huang et al, 2016 <https://arxiv.org/abs/1603.09382>`_) to the specified model.
 
     The algorithm replaces the specified target layer with a stochastic version
@@ -67,9 +67,6 @@ def apply_stochastic_depth(model: torch.nn.Module,
             starting with 0 drop rate and ending with ``drop_rate``.
             Default: ``"linear"``.
 
-    Returns:
-        The modified model
-
     Example:
         .. testcode::
 
@@ -95,7 +92,6 @@ def apply_stochastic_depth(model: torch.nn.Module,
                                                      stochastic_method=stochastic_method)
     transforms[target_layer] = stochastic_from_target_layer
     module_surgery.replace_module_classes(model, policies=transforms)
-    return model
 
 
 class StochasticDepth(Algorithm):

examples/exporting_for_inference.ipynb

@@ -80,7 +80,7 @@
     "import composer.functional as cf\n",
     "\n",
     "model = ComposerClassifier(module=resnet.resnet50())\n",
-    "model = cf.apply_squeeze_excite(model)\n",
+    "cf.apply_squeeze_excite(model)\n",
     "\n",
     "# switch to eval mode\n",
     "model.eval()"