[Minor] Sort safetensors files to ensure deterministic loading order (#33491)

Signed-off-by: Lihao Ran <imlihao.ran@gmail.com>
Signed-off-by: mgoin <mgoin64@gmail.com>
Co-authored-by: mgoin <mgoin64@gmail.com>

vllm/model_executor/model_loader/weight_utils.py

@@ -19,6 +19,7 @@ from typing import IO, Any
 import filelock
 import huggingface_hub.constants
 import numpy as np
+import regex as re
 import torch
 from huggingface_hub import HfFileSystem, hf_hub_download, snapshot_download
 from safetensors.torch import load, load_file, safe_open, save_file
@@ -143,6 +144,15 @@ def atomic_writer(
             os.remove(temp_path)
 
 
+def _natural_sort_key(filepath: str) -> list:
+    """Natural sort key for filenames with numeric components, such as
+    model-00001-of-00005.safetensors -> ['model-', 1, '-of-', 5, '.safetensors']"""
+    return [
+        int(s) if s.isdigit() else s
+        for s in re.split(r"(\d+)", os.path.basename(filepath))
+    ]
+
+
 def maybe_download_from_modelscope(
     model: str,
     revision: str | None = None,
@@ -682,9 +692,8 @@ def safetensors_weights_iterator(
         loading_desc += " (eager)"
 
     leftover_state_dict: dict[str, torch.Tensor] = {}
-
     for st_file in tqdm(
-        hf_weights_files,
+        sorted(hf_weights_files, key=_natural_sort_key),
         desc=loading_desc,
         disable=not enable_tqdm(use_tqdm_on_load),
         bar_format=_BAR_FORMAT,