diff --git a/docs/source/index.rst b/docs/source/index.rst
index 8457d4476a1c..00d455ed9ad4 100644
--- a/docs/source/index.rst
+++ b/docs/source/index.rst
@@ -161,11 +161,11 @@ Documentation
    design/multimodal/multimodal_index
    design/huggingface_integration
 
-.. Contributing: contributing to the vLLM project
+.. For Developers: contributing to the vLLM project
 
 .. toctree::
    :maxdepth: 2
-   :caption: Contributing
+   :caption: For Developers
 
    contributing/overview
    contributing/profiling/profiling_index
diff --git a/vllm/logger.py b/vllm/logger.py
index 80b9fcc59272..9e16e591315b 100644
--- a/vllm/logger.py
+++ b/vllm/logger.py
@@ -117,13 +117,14 @@ def _trace_calls(log_path, root_dir, frame, event, arg=None):
                 last_lineno = 0
                 last_func_name = ""
             with open(log_path, 'a') as f:
+                ts = datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S.%f")
                 if event == 'call':
-                    f.write(f"{datetime.datetime.now()} Call to"
+                    f.write(f"{ts} Call to"
                             f" {func_name} in {filename}:{lineno}"
                             f" from {last_func_name} in {last_filename}:"
                             f"{last_lineno}\n")
                 else:
-                    f.write(f"{datetime.datetime.now()} Return from"
+                    f.write(f"{ts} Return from"
                             f" {func_name} in {filename}:{lineno}"
                             f" to {last_func_name} in {last_filename}:"
                             f"{last_lineno}\n")
diff --git a/vllm/utils.py b/vllm/utils.py
index 13d7f6d47534..1b02cbff79f7 100644
--- a/vllm/utils.py
+++ b/vllm/utils.py
@@ -4,6 +4,7 @@ import contextlib
 import datetime
 import enum
 import gc
+import getpass
 import inspect
 import ipaddress
 import os
@@ -967,6 +968,8 @@ def enable_trace_function_call_for_thread() -> None:
 
     if envs.VLLM_TRACE_FUNCTION:
         tmp_dir = tempfile.gettempdir()
+        # add username to tmp_dir to avoid permission issues
+        tmp_dir = os.path.join(tmp_dir, getpass.getuser())
         filename = (f"VLLM_TRACE_FUNCTION_for_process_{os.getpid()}"
                     f"_thread_{threading.get_ident()}_"
                     f"at_{datetime.datetime.now()}.log").replace(" ", "_")