Fix flaky test execution caused by Thread (#34966)

fix

Co-authored-by: ydshieh <ydshieh@users.noreply.github.com>

src/transformers/modeling_utils.py

@@ -29,7 +29,7 @@ import warnings
 from contextlib import contextmanager
 from dataclasses import dataclass
 from functools import partial, wraps
-from threading import Thread
+from multiprocessing import Process
 from typing import Any, Callable, Dict, List, Optional, Set, Tuple, Union
 from zipfile import is_zipfile
 
@@ -3839,11 +3839,11 @@ class PreTrainedModel(nn.Module, ModuleUtilsMixin, GenerationMixin, PushToHubMix
                                     **has_file_kwargs,
                                 }
                                 if not has_file(pretrained_model_name_or_path, safe_weights_name, **has_file_kwargs):
-                                    Thread(
+                                    Process(
                                         target=auto_conversion,
                                         args=(pretrained_model_name_or_path,),
                                         kwargs={"ignore_errors_during_conversion": True, **cached_file_kwargs},
-                                        name="Thread-autoconversion",
+                                        name="Process-auto_conversion",
                                     ).start()
                         else:
                             # Otherwise, no PyTorch file was found, maybe there is a TF or Flax model file.