Support custom DeepEP tuning config (#6257)

python/sglang/srt/layers/moe/ep_moe/token_dispatcher.py

+import logging
+
 from sglang.srt.layers.quantization.deep_gemm import _ENABLE_JIT_DEEPGEMM
-from sglang.srt.utils import DeepEPMode
+from sglang.srt.managers.schedule_batch import global_server_args_dict
+from sglang.srt.utils import DeepEPMode, load_json_config
 
 try:
-    from deep_ep import Buffer
+    from deep_ep import Buffer, Config
 
     from sglang.srt.layers.quantization.fp8_kernel import (
         sglang_per_token_group_quant_fp8,
@@ -25,6 +28,8 @@ from sglang.srt.layers.moe.ep_moe.kernels import (
 )
 from sglang.srt.model_executor.forward_batch_info import ForwardMode
 
+logger = logging.getLogger(__name__)
+
 
 class DeepEPDispatchMode(IntEnum):
     NORMAL = auto()
@@ -32,7 +37,6 @@ class DeepEPDispatchMode(IntEnum):
 
 
 class DeepEPBuffer:
-
     _buffer = None
     _dispatch_mode: Optional[DeepEPDispatchMode] = None
     _hidden_size: Optional[int] = None
@@ -60,8 +64,10 @@ class DeepEPBuffer:
         if deepep_mode.enable_normal():
             hidden_bytes = hidden_size * param_bytes
             for config in (
-                Buffer.get_dispatch_config(group.size()),
-                Buffer.get_combine_config(group.size()),
+                _DeepEPConfig.get_instance().normal_dispatch_config
+                or Buffer.get_dispatch_config(group.size()),
+                _DeepEPConfig.get_instance().normal_combine_config
+                or Buffer.get_combine_config(group.size()),
             ):
                 num_nvl_bytes = max(
                     config.get_nvl_buffer_size_hint(hidden_bytes, group.size()),
@@ -113,6 +119,28 @@ class DeepEPBuffer:
         cls._dispatch_mode = DeepEPDispatchMode.LOW_LATENCY
 
 
+class _DeepEPConfig:
+    _instance = None
+
+    def __init__(self):
+        config_str = global_server_args_dict["deepep_config"]
+        if config_str:
+            config_parsed = load_json_config(config_str)
+            if torch.distributed.get_rank() == 0:
+                logger.info(f"Use DeepEP Config: {config_parsed}")
+            self.normal_dispatch_config = Config(**config_parsed["normal_dispatch"])
+            self.normal_combine_config = Config(**config_parsed["normal_combine"])
+        else:
+            self.normal_dispatch_config = None
+            self.normal_combine_config = None
+
+    @classmethod
+    def get_instance(cls):
+        if cls._instance is None:
+            cls._instance = _DeepEPConfig()
+        return cls._instance
+
+
 class _DeepEPDispatcherImplBase:
     def __init__(
         self,
@@ -295,6 +323,7 @@ class _DeepEPDispatcherImplNormal(_DeepEPDispatcherImplBase):
             async_finish=self.async_finish,
             allocate_on_comm_stream=(previous_event is not None) and self.async_finish,
             expert_alignment=128 if _ENABLE_JIT_DEEPGEMM else 1,
+            config=_DeepEPConfig.get_instance().normal_dispatch_config,
         )
 
         return (
@@ -394,6 +423,7 @@ class _DeepEPDispatcherImplNormal(_DeepEPDispatcherImplBase):
             async_finish=self.async_finish,
             previous_event=previous_event,
             allocate_on_comm_stream=previous_event is not None,
+            config=_DeepEPConfig.get_instance().normal_combine_config,
         )
         return combined_x, event
 

python/sglang/srt/managers/schedule_batch.py

@@ -77,6 +77,7 @@ global_server_args_dict = {
     "enable_dp_attention": ServerArgs.enable_dp_attention,
     "enable_dp_lm_head": ServerArgs.enable_dp_lm_head,
     "enable_ep_moe": ServerArgs.enable_ep_moe,
+    "deepep_config": ServerArgs.deepep_config,
     "enable_nan_detection": ServerArgs.enable_nan_detection,
     "flashinfer_mla_disable_ragged": ServerArgs.flashinfer_mla_disable_ragged,
     "max_micro_batch_size": ServerArgs.max_micro_batch_size,

python/sglang/srt/model_executor/model_runner.py

@@ -165,6 +165,7 @@ class ModelRunner:
                 "enable_dp_attention": server_args.enable_dp_attention,
                 "enable_ep_moe": server_args.enable_ep_moe,
                 "enable_deepep_moe": server_args.enable_deepep_moe,
+                "deepep_config": server_args.deepep_config,
                 "flashinfer_mla_disable_ragged": server_args.flashinfer_mla_disable_ragged,
                 "moe_dense_tp_size": server_args.moe_dense_tp_size,
                 "n_share_experts_fusion": server_args.n_share_experts_fusion,

python/sglang/srt/server_args.py

@@ -169,6 +169,7 @@ class ServerArgs:
     enable_ep_moe: bool = False
     enable_deepep_moe: bool = False
     deepep_mode: Optional[Literal["auto", "normal", "low_latency"]] = "auto"
+    deepep_config: Optional[str] = None
     enable_torch_compile: bool = False
     torch_compile_max_bs: int = 32
     cuda_graph_max_bs: Optional[int] = None
@@ -1249,6 +1250,12 @@ class ServerArgs:
             default="auto",
             help="Select the mode when enable DeepEP MoE, could be `normal`, `low_latency` or `auto`. Default is `auto`, which means `low_latency` for decode batch and `normal` for prefill batch.",
         )
+        parser.add_argument(
+            "--deepep-config",
+            type=str,
+            default=ServerArgs.deepep_config,
+            help="Tuned DeepEP config suitable for your own cluster.",
+        )
 
         parser.add_argument(
             "--n-share-experts-fusion",

python/sglang/srt/utils.py

@@ -2102,5 +2102,12 @@ def log_info_on_rank0(logger, msg):
         logger.info(msg)
 
 
+def load_json_config(data: str):
+    try:
+        return json.loads(data)
+    except JSONDecodeError:
+        return json.loads(Path(data).read_text())
+
+
 def dispose_tensor(x: torch.Tensor):
     x.set_(torch.empty((0,), device=x.device, dtype=x.dtype))

test/srt/test_moe_deepep.py

+import json
+import os
 import unittest
 from types import SimpleNamespace
 
@@ -64,8 +66,34 @@ class TestDPAttn(unittest.TestCase):
                 "2",
                 "--enable-dp-attention",
                 "--enable-deepep-moe",
+                "--deepep-mode",
+                "normal",
                 "--disable-cuda-graph",
+                # Test custom config
+                "--deepep-config",
+                json.dumps(
+                    {
+                        "normal_dispatch": {
+                            "num_sms": 20,
+                            "num_max_nvl_chunked_send_tokens": 16,
+                            "num_max_nvl_chunked_recv_tokens": 256,
+                            "num_max_rdma_chunked_send_tokens": 6,
+                            "num_max_rdma_chunked_recv_tokens": 128,
+                        },
+                        "normal_combine": {
+                            "num_sms": 20,
+                            "num_max_nvl_chunked_send_tokens": 6,
+                            "num_max_nvl_chunked_recv_tokens": 256,
+                            "num_max_rdma_chunked_send_tokens": 6,
+                            "num_max_rdma_chunked_recv_tokens": 128,
+                        },
+                    }
+                ),
             ],
+            env={
+                "SGL_ENABLE_JIT_DEEPGEMM": "0",
+                **os.environ,
+            },
         )
 
     @classmethod