Use dtype from model config & Add Dolly V2 (#63)

Author: WoosukKwon

cacheflow/master/server.py

@@ -214,7 +214,11 @@ def add_server_arguments(parser: argparse.ArgumentParser):
                         help='save a numpy copy of model weights for faster loading')
     parser.add_argument('--use-dummy-weights', action='store_true', help='use dummy values for model weights')
     # NOTE(woosuk): FlashAttention does not support float32.
-    parser.add_argument('--dtype', type=str, default='half', choices=['half', 'bfloat16'], help='data type')
+    parser.add_argument('--dtype', type=str, default='default', choices=['default', 'half', 'bfloat16'],
+                        help=('data type for model weights and activations. '
+                              'The "default" option will use FP16 precision '
+                              'for FP32 and FP16 models, and BF16 precision '
+                              'for BF16 models.'))
     # Parallel arguments
     parser.add_argument('--use-ray', action='store_true', help='use Ray for distributed serving, will be automatically set when using more than 1 GPU')
     parser.add_argument('--pipeline-parallel-size', '-pp', type=int, default=1, help='number of pipeline stages')

cacheflow/models/model_utils.py

@@ -1,8 +1,9 @@
-from typing import Union, Optional
+from typing import Optional
 
 import torch
 import torch.nn as nn
 from transformers import AutoConfig
+from transformers import PretrainedConfig
 
 from cacheflow.models.memory_analyzer import CacheFlowMemoryAnalyzer
 from cacheflow.models.memory_analyzer import GPT2MemoryAnalyzer
@@ -22,6 +23,7 @@
     'opt': OPTForCausalLM,
     'stablelm': GPTNeoXForCausalLM,
     'pythia': GPTNeoXForCausalLM,
+    'dolly-v2': GPTNeoXForCausalLM,
 }
 
 _MEMORY_ANALYZERS = {
@@ -30,19 +32,38 @@
     'opt': OPTMemoryAnalyzer,
     'stablelm': GPTNeoXMemoryAnalyzer,
     'pythia': GPTNeoXMemoryAnalyzer,
+    'dolly-v2': GPTNeoXMemoryAnalyzer,
 }
 
 
+def _get_dtype(config: PretrainedConfig, dtype: str) -> torch.dtype:
+    config_dtype: torch.dtype = getattr(config, 'torch_dtype', torch.float32)
+    if dtype == 'default':
+        if config_dtype == torch.float32:
+            # Following the common practice, we use float16 for float32 models.
+            torch_dtype = torch.float16
+        else:
+            torch_dtype = config_dtype
+    else:
+        torch_dtype = get_torch_dtype(dtype)
+        if torch_dtype != config_dtype and config_dtype != torch.float32:
+            # TODO(woosuk): Allow using float16 for bfloat16 models and
+            # vice versa. Print a warning message and continue.
+            raise ValueError(
+                f'Cannot use {torch_dtype} for {config_dtype} model.')
+    return torch_dtype
+
+
 def get_model(
     model_name: str,
-    dtype: Union[torch.dtype, str],
+    dtype: str,
     cache_dir: Optional[str],
     use_dummy_weights: bool,
     use_np_cache: bool,
 ) -> nn.Module:
-    torch_dtype = get_torch_dtype(dtype)
-    torch.set_default_dtype(torch_dtype)
     config = AutoConfig.from_pretrained(model_name)
+    torch_dtype = _get_dtype(config, dtype)
+    torch.set_default_dtype(torch_dtype)
     for model_class_name, model_class in _MODELS.items():
         if model_class_name in model_name:
             if use_dummy_weights:
@@ -66,12 +87,13 @@ def get_model(
 def get_memory_analyzer(
     model_name: str,
     block_size: int,
-    dtype: Union[torch.dtype, str],
+    dtype: str,
     gpu_memory: int,
     cpu_memory: int,
     tensor_parallel_size: int = 1,
 ) -> CacheFlowMemoryAnalyzer:
-    torch_dtype = get_torch_dtype(dtype)
+    config = AutoConfig.from_pretrained(model_name)
+    torch_dtype = _get_dtype(config, dtype)
     for model_class, memory_analyzer in _MEMORY_ANALYZERS.items():
         if model_class in model_name:
             return memory_analyzer(