Fix model info cache for package models

tests/models/test_registry.py

@@ -20,6 +20,7 @@
     _SPECULATIVE_DECODING_MODELS,
     _TEXT_GENERATION_MODELS,
     ModelRegistry,
+    _LazyRegisteredModel,
 )
 from vllm.platforms import current_platform
 
@@ -127,6 +128,22 @@ def test_registry_is_pp(model_arch, is_pp, init_cuda):
             )
 
 
+def test_lazy_modelinfo_package_hash_includes_submodules(tmp_path):
+    package_dir = tmp_path / "model_package"
+    package_dir.mkdir()
+    init_file = package_dir / "__init__.py"
+    init_file.write_text("from .model import Model\n", encoding="utf-8")
+    model_file = package_dir / "model.py"
+    model_file.write_text("class Model: pass\n", encoding="utf-8")
+
+    first_hash = _LazyRegisteredModel._get_modelinfo_module_hash(init_file)
+
+    model_file.write_text("class Model:\n    supports_pp = True\n", encoding="utf-8")
+    second_hash = _LazyRegisteredModel._get_modelinfo_module_hash(init_file)
+
+    assert first_hash != second_hash
+
+
 def test_hf_registry_coverage():
     untested_archs = (
         ModelRegistry.get_supported_archs() - HF_EXAMPLE_MODELS.get_supported_archs()

vllm/model_executor/models/registry.py

@@ -849,6 +849,25 @@ def _get_cache_filename(self) -> str:
         cls_name = f"{self.module_name}-{self.class_name}".replace(".", "-")
         return f"{cls_name}.json"
 
+    @staticmethod
+    def _get_modelinfo_module_hash(model_path: Path) -> str:
+        if model_path.name == "__init__.py":
+            # Package entry points often re-export classes implemented in
+            # submodules, so include the package contents in the cache key.
+            module_paths = sorted(model_path.parent.rglob("*.py"))
+            root_path = model_path.parent
+        else:
+            module_paths = [model_path]
+            root_path = model_path.parent
+
+        hasher = safe_hash(b"", usedforsecurity=False)
+        for path in module_paths:
+            hasher.update(path.relative_to(root_path).as_posix().encode("utf-8"))
+            hasher.update(b"\0")
+            hasher.update(path.read_bytes())
+            hasher.update(b"\0")
+        return hasher.hexdigest()
+
     def _load_modelinfo_from_cache(self, module_hash: str) -> _ModelInfo | None:
         try:
             try:
@@ -915,8 +934,7 @@ def inspect_model_cls(self) -> _ModelInfo:
         module_hash = None
 
         if model_path is not None and model_path.exists():
-            with open(model_path, "rb") as f:
-                module_hash = safe_hash(f.read(), usedforsecurity=False).hexdigest()
+            module_hash = self._get_modelinfo_module_hash(model_path)
 
             mi = self._load_modelinfo_from_cache(module_hash)
             if mi is not None: