[UNet3DModel] Fix with attn processor (#2790)

* [UNet3DModel] Fix attn processor

* make style

src/diffusers/models/unet_3d_condition.py

@@ -21,6 +21,7 @@ import torch.utils.checkpoint
 
 from ..configuration_utils import ConfigMixin, register_to_config
 from ..utils import BaseOutput, logging
+from .attention_processor import AttentionProcessor
 from .embeddings import TimestepEmbedding, Timesteps
 from .modeling_utils import ModelMixin
 from .transformer_temporal import TransformerTemporalModel
@@ -249,6 +250,32 @@ class UNet3DConditionModel(ModelMixin, ConfigMixin):
             block_out_channels[0], out_channels, kernel_size=conv_out_kernel, padding=conv_out_padding
         )
 
+    @property
+    # Copied from diffusers.models.unet_2d_condition.UNet2DConditionModel.attn_processors
+    def attn_processors(self) -> Dict[str, AttentionProcessor]:
+        r"""
+        Returns:
+            `dict` of attention processors: A dictionary containing all attention processors used in the model with
+            indexed by its weight name.
+        """
+        # set recursively
+        processors = {}
+
+        def fn_recursive_add_processors(name: str, module: torch.nn.Module, processors: Dict[str, AttentionProcessor]):
+            if hasattr(module, "set_processor"):
+                processors[f"{name}.processor"] = module.processor
+
+            for sub_name, child in module.named_children():
+                fn_recursive_add_processors(f"{name}.{sub_name}", child, processors)
+
+            return processors
+
+        for name, module in self.named_children():
+            fn_recursive_add_processors(name, module, processors)
+
+        return processors
+
+    # Copied from diffusers.models.unet_2d_condition.UNet2DConditionModel.set_attention_slice
     def set_attention_slice(self, slice_size):
         r"""
         Enable sliced attention computation.
@@ -259,24 +286,24 @@ class UNet3DConditionModel(ModelMixin, ConfigMixin):
         Args:
             slice_size (`str` or `int` or `list(int)`, *optional*, defaults to `"auto"`):
                 When `"auto"`, halves the input to the attention heads, so attention will be computed in two steps. If
-                `"max"`, maxium amount of memory will be saved by running only one slice at a time. If a number is
+                `"max"`, maximum amount of memory will be saved by running only one slice at a time. If a number is
                 provided, uses as many slices as `attention_head_dim // slice_size`. In this case, `attention_head_dim`
                 must be a multiple of `slice_size`.
         """
         sliceable_head_dims = []
 
-        def fn_recursive_retrieve_slicable_dims(module: torch.nn.Module):
+        def fn_recursive_retrieve_sliceable_dims(module: torch.nn.Module):
             if hasattr(module, "set_attention_slice"):
                 sliceable_head_dims.append(module.sliceable_head_dim)
 
             for child in module.children():
-                fn_recursive_retrieve_slicable_dims(child)
+                fn_recursive_retrieve_sliceable_dims(child)
 
         # retrieve number of attention layers
         for module in self.children():
-            fn_recursive_retrieve_slicable_dims(module)
+            fn_recursive_retrieve_sliceable_dims(module)
 
-        num_slicable_layers = len(sliceable_head_dims)
+        num_sliceable_layers = len(sliceable_head_dims)
 
         if slice_size == "auto":
             # half the attention head size is usually a good trade-off between
@@ -284,9 +311,9 @@ class UNet3DConditionModel(ModelMixin, ConfigMixin):
             slice_size = [dim // 2 for dim in sliceable_head_dims]
         elif slice_size == "max":
             # make smallest slice possible
-            slice_size = num_slicable_layers * [1]
+            slice_size = num_sliceable_layers * [1]
 
-        slice_size = num_slicable_layers * [slice_size] if not isinstance(slice_size, list) else slice_size
+        slice_size = num_sliceable_layers * [slice_size] if not isinstance(slice_size, list) else slice_size
 
         if len(slice_size) != len(sliceable_head_dims):
             raise ValueError(
@@ -314,6 +341,37 @@ class UNet3DConditionModel(ModelMixin, ConfigMixin):
         for module in self.children():
             fn_recursive_set_attention_slice(module, reversed_slice_size)
 
+    # Copied from diffusers.models.unet_2d_condition.UNet2DConditionModel.set_attn_processor
+    def set_attn_processor(self, processor: Union[AttentionProcessor, Dict[str, AttentionProcessor]]):
+        r"""
+        Parameters:
+            `processor (`dict` of `AttentionProcessor` or `AttentionProcessor`):
+                The instantiated processor class or a dictionary of processor classes that will be set as the processor
+                of **all** `Attention` layers.
+            In case `processor` is a dict, the key needs to define the path to the corresponding cross attention processor. This is strongly recommended when setting trainable attention processors.:
+
+        """
+        count = len(self.attn_processors.keys())
+
+        if isinstance(processor, dict) and len(processor) != count:
+            raise ValueError(
+                f"A dict of processors was passed, but the number of processors {len(processor)} does not match the"
+                f" number of attention layers: {count}. Please make sure to pass {count} processor classes."
+            )
+
+        def fn_recursive_attn_processor(name: str, module: torch.nn.Module, processor):
+            if hasattr(module, "set_processor"):
+                if not isinstance(processor, dict):
+                    module.set_processor(processor)
+                else:
+                    module.set_processor(processor.pop(f"{name}.processor"))
+
+            for sub_name, child in module.named_children():
+                fn_recursive_attn_processor(f"{name}.{sub_name}", child, processor)
+
+        for name, module in self.named_children():
+            fn_recursive_attn_processor(name, module, processor)
+
     def _set_gradient_checkpointing(self, module, value=False):
         if isinstance(module, (CrossAttnDownBlock3D, DownBlock3D, CrossAttnUpBlock3D, UpBlock3D)):
             module.gradient_checkpointing = value