[Perf] Disable inductor runtime asserts by default for serving perfor… (#37485)

Signed-off-by: tianrengao <terrygao87@gmail.com>
Co-authored-by: Tianren Gao <tianren@fb.com>

tests/compile/test_config.py

@@ -5,6 +5,7 @@ from contextlib import nullcontext
 from unittest.mock import MagicMock, patch
 
 import pytest
+import torch
 from pydantic import ValidationError
 
 from vllm.compilation.counter import compilation_counter
@@ -612,3 +613,58 @@ def test_adjust_cudagraph_sizes_for_mamba_cache(
     # Invariant: last element == max_cudagraph_capture_size
     if expected_sizes:
         assert config.cudagraph_capture_sizes[-1] == config.max_cudagraph_capture_size
+
+
+def test_inductor_asserts_default_disabled(monkeypatch):
+    """Test that inductor runtime asserts are disabled by default
+    (INFO logging level) on torch < 2.12."""
+    monkeypatch.setenv("VLLM_LOGGING_LEVEL", "INFO")
+
+    import importlib
+
+    import vllm.envs
+
+    importlib.reload(vllm.envs)
+
+    config = CompilationConfig()
+    if not _is_torch_equal_or_newer(torch.__version__, "2.12.0.dev"):
+        assert config.inductor_compile_config.get("size_asserts") is False
+        assert config.inductor_compile_config.get("alignment_asserts") is False
+        assert config.inductor_compile_config.get("scalar_asserts") is False
+
+
+def test_inductor_asserts_enabled_in_debug(monkeypatch):
+    """Test that VLLM_LOGGING_LEVEL=DEBUG enables inductor runtime asserts
+    on torch < 2.12."""
+    monkeypatch.setenv("VLLM_LOGGING_LEVEL", "DEBUG")
+
+    import importlib
+
+    import vllm.envs
+
+    importlib.reload(vllm.envs)
+
+    config = CompilationConfig()
+    if not _is_torch_equal_or_newer(torch.__version__, "2.12.0.dev"):
+        assert config.inductor_compile_config.get("size_asserts") is True
+        assert config.inductor_compile_config.get("alignment_asserts") is True
+        assert config.inductor_compile_config.get("scalar_asserts") is True
+
+
+def test_inductor_asserts_user_override(monkeypatch):
+    """Test that explicit inductor_compile_config overrides the
+    debug-logging default."""
+    monkeypatch.setenv("VLLM_LOGGING_LEVEL", "INFO")
+
+    import importlib
+
+    import vllm.envs
+
+    importlib.reload(vllm.envs)
+
+    config = CompilationConfig(
+        inductor_compile_config={"size_asserts": True},
+    )
+    assert config.inductor_compile_config.get("size_asserts") is True
+    if not _is_torch_equal_or_newer(torch.__version__, "2.12.0.dev"):
+        assert config.inductor_compile_config.get("alignment_asserts") is False