add vlmm backend (#274)

what this PR does:

- adds vllm as backend for faster inference.

how to use:

```
 lighteval accelerate --model_args="pretrained=meta-llama/Meta-Llama-3.1-8B-Instruct,dtype=bfloat16,vllm,data_parallel_size=2" use_chat_template --tasks "leaderboard|arc:challenge|0|0,extended|ifeval|0|0,lighteval|gsm8k|5|1" output_dir="./evals/"
```

---------

Co-authored-by: Clémentine Fourrier <[email protected]>

pyproject.toml

@@ -87,6 +87,7 @@ nanotron = [
   "tensorboardX"
 ]
 tensorboardX = ["tensorboardX"]
+vllm = ["vllm", "ray", "more_itertools"]
 quality = ["ruff==v0.2.2","pre-commit"]
 tests = ["pytest==7.4.0"]
 dev = ["lighteval[accelerate,quality,tests]"]

src/lighteval/data.py

@@ -161,6 +161,20 @@ def __len__(self) -> int:
         """
         return self.split_end - self.split_start
 
+    def __iter__(self) -> Iterator[Request]:
+        """
+        Iterator that yields the items of the dataset depending on the split we
+        are currently in. For instance, if we are in split 0, we will get the
+        items from index 0 to self.split_size, if we are in split 1, we will get
+        the items from index self.split_size to 2 * self.split_size, etc. Used
+        for dynamic batching.
+
+        Yields:
+            Any: The items of the dataset.
+        """
+        for i in range(self.split_start, self.split_end):
+            yield self.sorted_data[i]
+
     def _sorting_criteria(self, request) -> int:
         raise NotImplementedError()
 

src/lighteval/models/base_model.py

@@ -93,6 +93,7 @@ def __init__(
             hlog(f"Using Data Parallelism, putting model on device {self._device}")
             self.model = self.model.to(self._device)
         if config.compile:
+            hlog("Compiling the model")
             self.model.model.compile()
 
         self.model_name = _simplify_name(config.pretrained)
@@ -549,9 +550,9 @@ def greedy_until(
                 tokenized = self.tokenizer(
                     context,
                     truncation="longest_first",  # we truncate to the model max length if needed
-                    padding="longest",  # we pad to the longest sequence
+                    padding="max_length",  # we pad to the longest sequence
                     return_tensors="pt",
-                    max_length=self.max_length - 1,  # we always allow minimum one token of generation
+                    max_length=max_context_continuation_size_allowed,  # we always allow minimum one token of generation
                     add_special_tokens=self.add_special_tokens,
                 ).to(self.device)
 
@@ -573,7 +574,10 @@ def greedy_until(
                     if max_new_tokens is None:  # If generation size is not set, we go all the way
                         max_new_tokens = self.max_length - context_size
                     else:
+                        print(self.max_length, context_size, max_new_tokens)
                         max_new_tokens = min(self.max_length - context_size, max_new_tokens)
+                        if max_new_tokens < 1:
+                            max_new_tokens = 1
 
                 prepared_batch = Batch(
                     input_ids=tokenized["input_ids"],

src/lighteval/models/model_config.py

@@ -204,6 +204,25 @@ def init_configs(self, env_config: EnvConfig):
         return self._init_configs(self.base_model, env_config)
 
 
+@dataclass
+class VLLMModelConfig:
+    pretrained: str
+    gpu_memory_utilisation: float = 0.8
+    batch_size: int = -1
+    revision: str = "main"
+    dtype: str | None = None
+    tensor_parallel_size: int = 1
+    data_parallel_size: int = 1
+    max_model_length: int = 1024
+    swap_space: int = 4  # CPU swap space size (GiB) per GPU.
+    seed: int = 1234
+    trust_remote_code: bool = False
+    use_chat_template: bool = False
+    add_special_tokens: bool = True
+    multichoice_continuations_start_space: bool = True
+    subfolder: Optional[str] = None
+
+
 @dataclass
 class TGIModelConfig:
     inference_server_address: str
@@ -279,6 +298,7 @@ def create_model_config(  # noqa: C901
     TGIModelConfig,
     InferenceEndpointModelConfig,
     DummyModelConfig,
+    VLLMModelConfig,
 ]:
     """
     Create a model configuration based on the provided arguments.
@@ -313,6 +333,9 @@ def create_model_config(  # noqa: C901
         if model_args.pop("dummy", False):
             return DummyModelConfig(**model_args)
 
+        if model_args.pop("vllm", False):
+            return VLLMModelConfig(**model_args)
+
         model_args["accelerator"] = accelerator
         model_args["use_chat_template"] = use_chat_template
         model_args["compile"] = bool(model_args["compile"]) if "compile" in model_args else False

src/lighteval/models/model_loader.py

@@ -33,13 +33,15 @@
     BaseModelConfig,
     DeltaModelConfig,
     DummyModelConfig,
-    EnvConfig,
     InferenceEndpointModelConfig,
     InferenceModelConfig,
     TGIModelConfig,
+    VLLMModelConfig,
 )
 from lighteval.models.tgi_model import ModelClient
-from lighteval.utils.imports import NO_TGI_ERROR_MSG, is_tgi_available
+from lighteval.models.vllm_model import VLLMModel
+from lighteval.utils.imports import NO_TGI_ERROR_MSG, NO_VLLM_ERROR_MSG, is_tgi_available, is_vllm_available
+from lighteval.utils.utils import EnvConfig
 
 
 def load_model(  # noqa: C901
@@ -50,6 +52,7 @@ def load_model(  # noqa: C901
         TGIModelConfig,
         InferenceEndpointModelConfig,
         DummyModelConfig,
+        VLLMModelConfig,
     ],
     env_config: EnvConfig,
 ) -> Union[BaseModel, AdapterModel, DeltaModel, ModelClient, DummyModel]:
@@ -81,6 +84,9 @@ def load_model(  # noqa: C901
     if isinstance(config, DummyModelConfig):
         return load_dummy_model(config=config, env_config=env_config)
 
+    if isinstance(config, VLLMModelConfig):
+        return load_model_with_accelerate_or_default(config=config, env_config=env_config)
+
 
 def load_model_with_tgi(config: TGIModelConfig):
     if not is_tgi_available():
@@ -106,6 +112,11 @@ def load_model_with_accelerate_or_default(
         model = AdapterModel(config=config, env_config=env_config)
     elif isinstance(config, DeltaModelConfig):
         model = DeltaModel(config=config, env_config=env_config)
+    elif isinstance(config, VLLMModelConfig):
+        if not is_vllm_available():
+            raise ImportError(NO_VLLM_ERROR_MSG)
+        model = VLLMModel(config=config, env_config=env_config)
+        return model
     else:
         model = BaseModel(config=config, env_config=env_config)