feat: support deterministic FA4 for GLM-4.7-Flash (#33945)

test/registered/attention/test_glm4_moe_lite_deterministic.py

@@ -0,0 +1,68 @@
+"""Deterministic inference for GLM-4.7-Flash (Glm4MoeLiteForCausalLM) on Blackwell.
+
+Two entry paths matter. The fa4 backend is what this model needs for
+deterministic absorbed MLA, and the unspecified-backend path has to reach
+triton through the absorbed-MLA arch probe instead of the flashinfer default
+that every non-absorbed model gets on Blackwell.
+
+Usage:
+python3 -m unittest test_glm4_moe_lite_deterministic.TestGlm4MoeLiteFa4Deterministic
+"""
+
+import unittest
+
+import requests
+
+from sglang.test.ci.ci_register import register_cuda_ci
+from sglang.test.test_deterministic_utils import (
+    COMMON_SERVER_ARGS,
+    TestDeterministicBase,
+)
+from sglang.test.test_utils import DEFAULT_URL_FOR_TEST
+
+register_cuda_ci(est_time=900, stage="nightly", runner_config="4-gpu-gb300")
+
+GLM_MODEL = "zai-org/GLM-4.7-Flash"
+
+# COMMON_SERVER_ARGS is shared module state; copy it. Extending it in place
+# would leak the fa4 flag into the auto class below and silently make that
+# test a second fa4 test.
+SERVER_ARGS = COMMON_SERVER_ARGS + [
+    "--chunked-prefill-size",
+    "2048",
+    "--max-prefill-tokens",
+    "2048",
+    "--mem-fraction-static",
+    "0.8",
+]
+
+
+class TestGlm4MoeLiteFa4Deterministic(TestDeterministicBase):
+    @classmethod
+    def get_model(cls):
+        return GLM_MODEL
+
+    @classmethod
+    def get_server_args(cls):
+        return SERVER_ARGS + ["--attention-backend", "fa4"]
+
+
+class TestGlm4MoeLiteAutoBackendDeterministic(TestDeterministicBase):
+    @classmethod
+    def get_model(cls):
+        return GLM_MODEL
+
+    @classmethod
+    def get_server_args(cls):
+        return SERVER_ARGS
+
+    def test_auto_backend_resolves_to_triton(self):
+        # Guards the arch probe itself: if Glm4MoeLiteForCausalLM stopped
+        # counting as absorbed MLA the fill would hand back flashinfer, which
+        # deterministic inference then rejects at launch.
+        info = requests.get(DEFAULT_URL_FOR_TEST + "/server_info").json()
+        self.assertEqual(info["attention_backend"], "triton")
+
+
+if __name__ == "__main__":
+    unittest.main()