fix: set_kernel_name returns None for unexpected activity kinds

src/sol_execbench/core/bench/cupti_utils.py

@@ -80,7 +80,9 @@ def set_kernel_name(activity):
             return "MEMCPY"
         if activity.kind == cupti.ActivityKind.MEMSET:
             return "MEMSET"
-        return None
+        # Activities such as RUNTIME or DRIVER may not provide a name. Fall
+        # back to a stable string so callers always receive a `str`.
+        return getattr(activity, "name", None) or str(activity.kind)
 
     @staticmethod
     def get_bytes(activity):

tests/core/bench/test_cupti_utils.py

@@ -0,0 +1,28 @@
+# SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+"""Tests for CUPTI activity normalization helpers."""
+
+import types
+import pytest
+
+from sol_execbench.core.bench.cupti_utils import CuptiKernelInfo
+
+
+def test_kernel_string_for_activity_without_name():
+    """Unexpected activity kinds without a name must still produce a string identity."""
+    activity = types.SimpleNamespace(
+        kind="RUNTIME",
+        name=None,
+        start=0.0,
+        end=1.0,
+        correlation_id=0,
+        bytes=0,
+        copy_kind=0,
+        value=0,
+    )
+    info = CuptiKernelInfo.from_activity(activity)
+    assert isinstance(info.name, str)
+    assert info.kernel_string() == "RUNTIME_0_0_0_RUNTIME"
+
+