fix unsloth and support device_map (#5139)

Co-authored-by: tastelikefeet <[email protected]>

Author: 2 people

swift/llm/argument/base_args/base_args.py

@@ -216,7 +216,6 @@ def load_args_from_ckpt(self) -> None:
             old_args = json.load(f)
         force_load_keys = [
             # base_args
-            'tuner_backend',
             'train_type',
             # model_args
             'task_type',

swift/llm/model/register.py

@@ -141,9 +141,10 @@ def load_by_unsloth(args):
         model_name=args.adapters and args.adapters[0] or args.model_dir,
         dtype=args.torch_dtype,
         max_seq_length=args.max_length,
-        full_finetuning=args.quant_bits is None,
+        full_finetuning=args.train_type == 'full',
         load_in_4bit=args.quant_bits == 4,
         load_in_8bit=args.quant_bits == 8,
+        device_map=args.device_map,
     )
     if isinstance(model, PeftModel):
         base_model = model.model