[BE][Bugfix] Respect TORCH_COMPILE_DISABLE env var at the vLLM config level for torch 2.12 (#40715)

Signed-off-by: Lucas Kabela <lucaskabela@meta.com>

tests/compile/test_config.py

@@ -205,6 +205,22 @@ def test_enforce_eager(vllm_runner, monkeypatch):
         pass
 
 
+@pytest.mark.forked
+def test_torch_compile_disable(vllm_runner, monkeypatch):
+    monkeypatch.setenv("VLLM_ENABLE_V1_MULTIPROCESSING", "0")
+    monkeypatch.setenv("TORCH_COMPILE_DISABLE", "1")
+    monkeypatch.setenv("VLLM_DISABLE_COMPILE_CACHE", "1")
+
+    with (
+        compilation_counter.expect(num_graphs_seen=0, stock_torch_compile_count=0),
+        vllm_runner(
+            "facebook/opt-125m",
+            gpu_memory_utilization=0.4,
+        ) as _,
+    ):
+        pass
+
+
 def test_splitting_ops_dynamic():
     # Default config
     config = VllmConfig()

vllm/config/vllm.py

@@ -900,6 +900,13 @@ class VllmConfig:
             self.compilation_config.mode = CompilationMode.NONE
             self.compilation_config.cudagraph_mode = CUDAGraphMode.NONE
 
+        if os.environ.get("TORCH_COMPILE_DISABLE") == "1":
+            logger.warning(
+                "TORCH_COMPILE_DISABLE is set, disabling torch.compile. "
+                "This is equivalent to setting -cc.mode=none"
+            )
+            self.compilation_config.mode = CompilationMode.NONE
+
         if self.compilation_config.backend == "eager" or (
             self.compilation_config.mode is not None
             and self.compilation_config.mode != CompilationMode.VLLM_COMPILE