[torch.compile] generic decorators (vllm-project#9258)

vllm/compilation/decorators.py

@@ -1,20 +1,54 @@
-from typing import List, Optional, Union
+import inspect
+from typing import Dict, List, Union
 
 import torch
 
 import vllm.envs as envs
-from vllm.attention import AttentionMetadata
 from vllm.compilation.levels import CompilationLevel
 from vllm.compilation.wrapper import TorchCompileWrapperWithCustomDispatcher
 from vllm.sequence import IntermediateTensors
 from vllm.utils import supports_dynamo
 
 
-def support_compile_llama_style(cls: type):
+def support_torch_compile(dynamic_arg_dims: Dict[str, Union[int, List[int]]]):
+    """
+    A decorator to add support for compiling the forward method of a class.
+
+    `dynamic_arg_dims` is a dictionary that maps argument names to the dynamic
+    dimensions of the argument. The dynamic dimensions can be either a single
+    integer or a list of integers.
+
+    Depending on the value of arguments:
+
+    - if it is a single integer, the corresponding dimension of the argument
+        will be marked as dynamic.
+    - if it is `None`, ignored.
+    - if it is `IntermediateTensors`, all the tensors in the intermediate
+        tensors will be marked as dynamic.
+    - otherwise, it will raise an error.
+
+    NOTE: if an argument is `None`, it should always be passed as `None` during
+    the lifetime of the model, otherwise, it cannot be captured as a single
+    computation graph.
+    """
+
+    def cls_decorator_helper(cls: type):
+        # helper to pass `dynamic_arg_dims`` to `_support_torch_compile``
+        # to avoid too much indentation for `_support_torch_compile``
+        sig = inspect.signature(cls.forward)
+        for k in dynamic_arg_dims:
+            if k not in sig.parameters:
+                raise ValueError(
+                    f"Argument {k} not found in the forward method of {cls}")
+        return _support_torch_compile(cls, dynamic_arg_dims)
+
+    return cls_decorator_helper
+
+
+def _support_torch_compile(cls: type,
+                           dynamic_arg_dims: Dict[str, Union[int, List[int]]]):
     """
     A decorator to add support for compiling the forward method of a class.
-    If a module's **forward signature** is compatible with llama, this 
-    decorator can be used to enable the compilation of the forward method.
     """
 
     # for CompilationLevel.DYNAMO_AS_IS , the upper level model runner
@@ -37,48 +71,42 @@ def __init__(self, *args, **kwargs):
 
     cls.__init__ = __init__
 
-    def __call__(
-        self,
-        input_ids: Optional[torch.Tensor],
-        positions: torch.Tensor,
-        kv_caches: List[torch.Tensor],
-        attn_metadata: AttentionMetadata,
-        intermediate_tensors: Optional[IntermediateTensors],
-        inputs_embeds: Optional[torch.Tensor] = None,
-    ) -> Union[torch.Tensor, IntermediateTensors]:
+    def __call__(self, *args, **kwargs):
         # torch.compiler.is_compiling() means we are inside the compilation
         # e.g. TPU has the compilation logic in model runner, so we don't
         # need to compile the model inside.
         if torch.compiler.is_compiling():
-            return self.forward(input_ids, positions, kv_caches, attn_metadata,
-                                intermediate_tensors, inputs_embeds)
+            return self.forward(*args, **kwargs)
 
         # the first compilation needs to have dynamic shapes marked
         if len(self.compiled_codes) < 1:
-            if input_ids is not None:
-                torch._dynamo.mark_dynamic(input_ids, 0)
-            torch._dynamo.mark_dynamic(positions, 0)
-            if inputs_embeds is not None:
-                torch._dynamo.mark_dynamic(inputs_embeds, 0)
-            if intermediate_tensors is not None:
-                for tensors in intermediate_tensors.tensors.values():
-                    torch._dynamo.mark_dynamic(tensors, 0)
+            sig = inspect.signature(self.__class__.forward)
+            bound_args = sig.bind(self, *args, **kwargs)
+            bound_args.apply_defaults()
+            for k, dims in dynamic_arg_dims.items():
+                arg = bound_args.arguments.get(k)
+                if arg is not None:
+                    if isinstance(arg, torch.Tensor):
+                        torch._dynamo.mark_dynamic(arg, dims)
+                    elif isinstance(arg, IntermediateTensors):
+                        for tensor in arg.tensors.values():
+                            torch._dynamo.mark_dynamic(tensor, dims)
+                    else:
+                        raise ValueError(
+                            "Unsupported dynamic dimensions"
+                            f" {dims} for argument {k} with type {type(arg)}.")
 
         # if we don't use custom dispatcher, we can directly call the
         # compiled function and let torch.compile handle the dispatching,
         # with the overhead of guard evaluation and recompilation.
         if len(self.compiled_codes) < 1 or not self.use_custom_dispatcher:
-            return self.compiled_callable(input_ids, positions, kv_caches,
-                                          attn_metadata, intermediate_tensors,
-                                          inputs_embeds)
+            return self.compiled_callable(*args, **kwargs)
 
         # usually, capturing the model once is enough, and then we can
         # dispatch to the compiled code directly, without going through
         # the Dynamo guard mechanism.
         with self.dispatch_to_code(0):
-            model_output = self.forward(input_ids, positions, kv_caches,
-                                        attn_metadata, intermediate_tensors,
-                                        inputs_embeds)
+            model_output = self.forward(*args, **kwargs)
             return model_output
 
     cls.__call__ = __call__

vllm/model_executor/models/gemma2.py

@@ -21,7 +21,7 @@
 from transformers import Gemma2Config
 
 from vllm.attention import Attention, AttentionMetadata
-from vllm.compilation.decorators import support_compile_llama_style
+from vllm.compilation.decorators import support_torch_compile
 from vllm.config import CacheConfig, LoRAConfig
 from vllm.distributed import get_pp_group, get_tensor_model_parallel_world_size
 from vllm.logger import init_logger
@@ -239,7 +239,13 @@ def forward(
         return hidden_states, residual
 
 
-@support_compile_llama_style
+@support_torch_compile(
+    dynamic_arg_dims={
+        "input_ids": 0,
+        "positions": 0,
+        "inputs_embeds": 0,
+        "intermediate_tensors": 0,
+    })
 class Gemma2Model(nn.Module):
 
     def __init__(

vllm/model_executor/models/llama.py

@@ -28,7 +28,7 @@
 from transformers import LlamaConfig
 
 from vllm.attention import Attention, AttentionMetadata
-from vllm.compilation.decorators import support_compile_llama_style
+from vllm.compilation.decorators import support_torch_compile
 from vllm.config import CacheConfig, LoRAConfig
 from vllm.distributed import (get_pp_group, get_tensor_model_parallel_rank,
                               get_tensor_model_parallel_world_size)
@@ -266,7 +266,13 @@ def forward(
         return hidden_states, residual
 
 
-@support_compile_llama_style
+@support_torch_compile(
+    dynamic_arg_dims={
+        "input_ids": 0,
+        "positions": 0,
+        "inputs_embeds": 0,
+        "intermediate_tensors": 0,
+    })
 class LlamaModel(nn.Module):
 
     def __init__(