[Fix] MoE: fix w8a8_fp8 MoE and add tests to cover this code path (#10429)

python/sglang/srt/layers/quantization/w8a8_fp8.py

@@ -5,6 +5,7 @@ from typing import TYPE_CHECKING, Any, Dict, List, Optional
 import torch
 from torch.nn.parameter import Parameter
 
+from sglang.srt.layers.moe import MoeRunner, MoeRunnerBackend, MoeRunnerConfig
 from sglang.srt.layers.moe.moe_runner.triton import TritonMoeQuantInfo
 from sglang.srt.layers.parameter import ChannelQuantScaleParameter, ModelWeightParameter
 from sglang.srt.layers.quantization.base_config import (
@@ -27,7 +28,6 @@ from sglang.srt.layers.quantization.fp8_utils import (
 from sglang.srt.utils import set_weight_attrs
 
 if TYPE_CHECKING:
-    from sglang.srt.layers.moe import MoeRunner, MoeRunnerBackend, MoeRunnerConfig
     from sglang.srt.layers.moe.token_dispatcher import (
         CombineInput,
         StandardDispatchOutput,

test/srt/quant/test_w8a8_quantization.py

@@ -14,23 +14,39 @@ from sglang.test.test_utils import (
 )
 
 
-class TestW8A8(CustomTestCase):
+class BaseW8A8Test(CustomTestCase):
+    model: str = None
+    quantization: str = None
+    gsm8k_accuracy_threshold: float = None
+    throughput_threshold: float = None
+
     @classmethod
     def setUpClass(cls):
-        cls.model = "neuralmagic/Meta-Llama-3-8B-Instruct-quantized.w8a8"
+        if cls is BaseW8A8Test:
+            raise unittest.SkipTest("Skip base test class")
+
         cls.base_url = DEFAULT_URL_FOR_TEST
+        other_args = []
+        if cls.quantization:
+            other_args.extend(["--quantization", cls.quantization])
+
         cls.process = popen_launch_server(
             cls.model,
             cls.base_url,
             timeout=DEFAULT_TIMEOUT_FOR_SERVER_LAUNCH,
-            other_args=["--quantization", "w8a8_int8"],
+            other_args=other_args,
         )
 
     @classmethod
     def tearDownClass(cls):
+        if cls is BaseW8A8Test:
+            return
         kill_process_tree(cls.process.pid)
 
     def test_gsm8k(self):
+        if self.gsm8k_accuracy_threshold is None:
+            self.skipTest("gsm8k_accuracy_threshold not set for this test")
+
         args = SimpleNamespace(
             num_shots=5,
             data_path=None,
@@ -42,8 +58,7 @@ class TestW8A8(CustomTestCase):
         )
         metrics = run_eval(args)
         print(metrics)
-
-        self.assertGreater(metrics["accuracy"], 0.69)
+        self.assertGreater(metrics["accuracy"], self.gsm8k_accuracy_threshold)
 
     def run_decode(self, max_new_tokens):
         response = requests.post(
@@ -60,15 +75,36 @@ class TestW8A8(CustomTestCase):
         return response.json()
 
     def test_throughput(self):
-        max_tokens = 256
 
+        max_tokens = 256
         tic = time.perf_counter()
         res = self.run_decode(max_tokens)
         tok = time.perf_counter()
         print(res["text"])
         throughput = max_tokens / (tok - tic)
         print(f"Throughput: {throughput} tokens/s")
-        assert throughput >= 140
+        self.assertGreaterEqual(throughput, self.throughput_threshold)
+
+
+class TestW8A8Int8(BaseW8A8Test):
+    model = "neuralmagic/Meta-Llama-3-8B-Instruct-quantized.w8a8"
+    quantization = "w8a8_int8"
+    gsm8k_accuracy_threshold = 0.69
+    throughput_threshold = 200
+
+
+class TestW8A8Fp8(BaseW8A8Test):
+    model = "neuralmagic/Meta-Llama-3.1-8B-Instruct-FP8-dynamic"
+    quantization = "w8a8_fp8"
+    gsm8k_accuracy_threshold = 0.69
+    throughput_threshold = 200
+
+
+class TestW8A8Fp8MoE(BaseW8A8Test):
+    model = "RedHatAI/Qwen3-30B-A3B-FP8-dynamic"
+    quantization = "w8a8_fp8"
+    gsm8k_accuracy_threshold = 0.88
+    throughput_threshold = 180
 
 
 if __name__ == "__main__":