Fix gemma3n with hybrid swa (#8240)

Signed-off-by: Xinyuan Tong <xinyuantong.cs@gmail.com>
Co-authored-by: Xinyuan Tong <xinyuantong.cs@gmail.com>

python/sglang/srt/model_executor/model_runner.py

@@ -276,6 +276,7 @@ class ModelRunner:
         self.sampler = Sampler()
         self.load_model()
 
+        # Check if the model is using hybrid SWA
         if (
             not self.server_args.disable_hybrid_swa_memory
             and self.sliding_window_size is not None
@@ -1008,8 +1009,11 @@ class ModelRunner:
                 try:
                     layers = self.model.language_model.model.layers
                 except:
-                    self.is_hybrid = False
-                    return
+                    try:
+                        layers = self.model.language_model.layers
+                    except:
+                        self.is_hybrid = False
+                        return
 
             for layer in layers:
                 if (

test/srt/run_suite.py

@@ -105,7 +105,7 @@ suites = {
         TestFile("test_vision_chunked_prefill.py", 175),
         TestFile("test_vlm_input_format.py", 300),
         TestFile("test_vision_openai_server_a.py", 584),
-        TestFile("test_vision_openai_server_b.py", 556),
+        TestFile("test_vision_openai_server_b.py", 620),
         TestFile("test_w8a8_quantization.py", 46),
         TestFile("test_reasoning_parser.py", 5),
     ],

test/srt/test_vision_openai_server_b.py

@@ -151,6 +151,27 @@ class TestGemma3itServer(TestOpenAIVisionServer):
         pass
 
 
+class TestGemma3nServer(TestOpenAIVisionServer):
+    @classmethod
+    def setUpClass(cls):
+        cls.model = "google/gemma-3n-E2B-it"
+        cls.base_url = DEFAULT_URL_FOR_TEST
+        cls.api_key = "sk-123456"
+        cls.process = popen_launch_server(
+            cls.model,
+            cls.base_url,
+            timeout=DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
+            other_args=[
+                "--trust-remote-code",
+                "--mem-fraction-static",
+                "0.70",
+                "--cuda-graph-max-bs",
+                "1",
+            ],
+        )
+        cls.base_url += "/v1"
+
+
 class TestKimiVLServer(TestOpenAIVisionServer):
     @classmethod
     def setUpClass(cls):