[compile] aot_compile should respect VLLM_DISABLE_COMPILE_CACHE (#36358)

Signed-off-by: Richard Zou <zou3519@gmail.com>

tests/compile/test_aot_compile.py

@@ -4,6 +4,7 @@
 import functools
 import hashlib
 import multiprocessing
+import os
 import pickle
 import tempfile
 from contextlib import contextmanager
@@ -19,6 +20,7 @@ from vllm.compilation.caching import (
     StandaloneCompiledArtifacts,
     VllmSerializableFunction,
 )
+from vllm.compilation.counter import compilation_counter
 from vllm.compilation.decorators import support_torch_compile
 from vllm.config import (
     CompilationConfig,
@@ -763,3 +765,115 @@ class TestStandaloneCompiledArtifactsIntegration:
         assert isinstance(config, dict)
         assert "bundled_autograd_cache" in config
         assert config["bundled_autograd_cache"] is True
+
+
+@pytest.mark.skipif(not is_torch_equal_or_newer("2.10.0"), reason="requires torch 2.10")
+def test_disable_compile_cache_skips_aot_save(
+    monkeypatch: pytest.MonkeyPatch, fresh_vllm_cache: str
+):
+    """When VLLM_DISABLE_COMPILE_CACHE=1, AOT artifacts must not be saved."""
+    monkeypatch.setenv("VLLM_DISABLE_COMPILE_CACHE", "1")
+    monkeypatch.setenv("VLLM_USE_AOT_COMPILE", "1")
+    disable_envs_cache()
+
+    args = (torch.randn(10, 10),)
+    expected = reference_fn(*args)
+    vllm_config = make_vllm_config()
+
+    with (
+        use_vllm_config(vllm_config),
+        compilation_counter.expect(
+            num_aot_compiles=1,
+            num_aot_artifacts_saved=0,
+            num_aot_artifacts_loaded=0,
+        ),
+    ):
+        mod = CompiledMod(vllm_config=vllm_config)
+        actual = mod(*args)
+
+    assert torch.allclose(actual, expected)
+
+    # No cached artifact should exist on disk
+    aot_dir = os.path.join(fresh_vllm_cache, "torch_compile_cache", "torch_aot_compile")
+    if os.path.isdir(aot_dir):
+        for root, _dirs, files in os.walk(aot_dir):
+            for f in files:
+                assert f != "model", (
+                    f"AOT artifact unexpectedly saved at {os.path.join(root, f)}"
+                )
+
+
+@pytest.mark.skipif(not is_torch_equal_or_newer("2.10.0"), reason="requires torch 2.10")
+def test_disable_compile_cache_skips_aot_load(
+    monkeypatch: pytest.MonkeyPatch, fresh_vllm_cache: str
+):
+    """When VLLM_DISABLE_COMPILE_CACHE=1, AOT artifacts must not be loaded."""
+    # Phase 1: compile and save with cache enabled
+    monkeypatch.setenv("VLLM_USE_AOT_COMPILE", "1")
+    disable_envs_cache()
+
+    args = (torch.randn(10, 10),)
+    vllm_config = make_vllm_config()
+
+    with (
+        use_vllm_config(vllm_config),
+        compilation_counter.expect(num_aot_artifacts_saved=1),
+    ):
+        CompiledMod(vllm_config=vllm_config)(*args)
+
+    # Phase 2: disable cache, compile again — should NOT load from disk
+    monkeypatch.setenv("VLLM_DISABLE_COMPILE_CACHE", "1")
+    disable_envs_cache()
+    torch._dynamo.reset()
+
+    vllm_config = make_vllm_config()
+    with (
+        use_vllm_config(vllm_config),
+        compilation_counter.expect(
+            num_aot_compiles=1,
+            num_aot_artifacts_saved=0,
+            num_aot_artifacts_loaded=0,
+        ),
+    ):
+        mod = CompiledMod(vllm_config=vllm_config)
+        mod(*args)
+
+    assert not mod.was_aot_compile_fn_loaded_from_disk
+
+
+@pytest.mark.skipif(not is_torch_equal_or_newer("2.10.0"), reason="requires torch 2.10")
+def test_aot_counters_on_save_and_load(
+    monkeypatch: pytest.MonkeyPatch, fresh_vllm_cache: str
+):
+    """Verify AOT counters are incremented correctly on save and load."""
+    monkeypatch.setenv("VLLM_USE_AOT_COMPILE", "1")
+    disable_envs_cache()
+
+    args = (torch.randn(10, 10),)
+
+    # Phase 1: fresh compile + save
+    vllm_config = make_vllm_config()
+    with (
+        use_vllm_config(vllm_config),
+        compilation_counter.expect(
+            num_aot_compiles=1,
+            num_aot_artifacts_saved=1,
+            num_aot_artifacts_loaded=0,
+        ),
+    ):
+        CompiledMod(vllm_config=vllm_config)(*args)
+
+    # Phase 2: load from cache
+    monkeypatch.setenv("VLLM_FORCE_AOT_LOAD", "1")
+    disable_envs_cache()
+
+    vllm_config = make_vllm_config()
+    with (
+        use_vllm_config(vllm_config),
+        compilation_counter.expect(
+            num_aot_compiles=0,
+            num_aot_artifacts_saved=0,
+            num_aot_artifacts_loaded=1,
+        ),
+    ):
+        CompiledMod(vllm_config=vllm_config)(*args)