Add an option to use dummy model weights (#33)

benchmark/benchmark_latency.py

@@ -29,6 +29,7 @@ def main(args: argparse.Namespace):
     server = Server(
         model=args.model,
         model_path=args.model_path,
+        use_dummy_weights=args.use_dummy_weights,
         pipeline_parallel_size=args.pipeline_parallel_size,
         tensor_parallel_size=args.tensor_parallel_size,
         block_size=args.block_size,

cacheflow/http_frontend/fastapi_frontend.py

@@ -47,6 +47,7 @@ class FastAPIFrontend:
         self.server = remote_server_class.remote(
             model=model,
             model_path=model_path,
+            use_dummy_weights=False,
             pipeline_parallel_size=pipeline_parallel_size,
             tensor_parallel_size=tensor_parallel_size,
             block_size=block_size,

cacheflow/master/server.py

@@ -16,6 +16,7 @@ class Server:
         self,
         model: str,
         model_path: str,
+        use_dummy_weights: bool,
         pipeline_parallel_size: int,
         tensor_parallel_size: int,
         block_size: int,
@@ -66,6 +67,7 @@ class Server:
                 dtype=dtype,
                 seed=seed,
                 model_path=model_path,
+                use_dummy_weights=use_dummy_weights,
                 max_num_batched_tokens=max_num_batched_tokens,
             )
             self.controllers.append(controller)
@@ -179,4 +181,5 @@ def add_server_arguments(parser: argparse.ArgumentParser):
     parser.add_argument('--seed', type=int, default=0, help='random seed')
     parser.add_argument('--swap-space', type=int, default=20, help='CPU swap space size (GiB) per GPU')
     parser.add_argument('--max-num-batched-tokens', type=int, default=2560, help='maximum number of batched tokens')
+    parser.add_argument('--use-dummy-weights', action='store_true', help='use dummy values for model weights')
     return parser

cacheflow/models/llama.py

@@ -286,3 +286,7 @@ class LlamaForCausalLM(nn.Module):
                         np.save(f, param.cpu().detach().numpy())
 
             return path
+
+    def initialize_dummy_weights(self) -> None:
+        for param in self.state_dict().values():
+            param.data.uniform_(-0.1, 0.1)

cacheflow/models/model_utils.py

@@ -28,18 +28,29 @@ def get_model(
     model_name: str,
     dtype: Union[torch.dtype, str],
     path: str,
+    use_dummy_weights: bool,
 ) -> nn.Module:
     torch_dtype = get_torch_dtype(dtype)
     torch.set_default_dtype(torch_dtype)
     config = AutoConfig.from_pretrained(model_name)
     for model_class_name, model_class in _MODELS.items():
         if model_class_name in model_name:
+            if use_dummy_weights:
+                # Create a model instance.
+                # The weights will be initialized as empty tensors.
+                model = model_class(config)
+                model = model.cuda()
+                # NOTE(woosuk): For precise performance evaluation, we assign
+                # random values to the weights. 
+                model.initialize_dummy_weights()
+            else:
                 # Download model weights if it's not cached.
                 weights_dir = model_class.get_weights(model_name, path=path)
                 # Create a model instance.
                 model = model_class(config)
                 # Load the weights from the cached or downloaded files.
                 model.load_weights(weights_dir)
+                model = model.cuda()
             return model.eval(), torch_dtype
     raise ValueError(f'Unsupported model name: {model_name}')
 

cacheflow/models/opt.py

@@ -324,3 +324,7 @@ class OPTForCausalLM(nn.Module):
                         np.save(f, param.cpu().detach().numpy())
 
             return path
+
+    def initialize_dummy_weights(self) -> None:
+        for param in self.state_dict().values():
+            param.data.uniform_(-0.1, 0.1)

cacheflow/worker/controller.py

@@ -27,6 +27,7 @@ class Controller:
         dtype: str,
         seed: int,
         model_path: str,
+        use_dummy_weights: bool,
         max_num_batched_tokens: int,
     ) -> None:
         self.stage_id = stage_id
@@ -58,6 +59,7 @@ class Controller:
                 tensor_parallel_size=tensor_parallel_size,
                 pipeline_parallel_size=pipeline_parallel_size,
                 model_path=model_path,
+                use_dummy_weights=use_dummy_weights,
                 max_num_batched_tokens=max_num_batched_tokens,
             )
             self.workers.append(worker)

cacheflow/worker/worker.py

@@ -29,6 +29,7 @@ class Worker:
         rank: int,
         world_size: int,
         model_path: str,
+        use_dummy_weights: bool,
         max_num_batched_tokens: int,
         tensor_parallel_size: int = 1,
         pipeline_parallel_size: int = 1,
@@ -43,8 +44,8 @@ class Worker:
         set_random_seed(seed)
 
         # Initialize the model.
-        self.model, self.dtype = get_model(model_name, dtype=dtype, path=model_path)
-        self.model = self.model.cuda()
+        self.model, self.dtype = get_model(
+            model_name, dtype=dtype, path=model_path, use_dummy_weights=use_dummy_weights)
         tensor_model_parallel_world_size = (
             get_tensor_model_parallel_world_size())
         initialize_all_reduce_launcher(

simple_server.py

@@ -22,6 +22,7 @@ def main(args: argparse.Namespace):
     server = Server(
         model=args.model,
         model_path=args.model_path,
+        use_dummy_weights=args.use_dummy_weights,
         pipeline_parallel_size=args.pipeline_parallel_size,
         tensor_parallel_size=args.tensor_parallel_size,
         block_size=args.block_size,