Release/0.6.2.post3: carry kt-kernel SwiGLU clamp companion missing from post2

kt-kernel/python/experts.py

@@ -143,6 +143,12 @@ class KTMoEWrapper:
         # Quantization config (for K-Group SFT methods)
         group_size: int = 128,
         zero_point: bool = True,
+        # V4-Flash 2604B SwiGLU clamp limit. 0.0 = disabled (default for
+        # every dtype except DSV4-2604B routed experts, which set this to
+        # 10.0 to match trtllm gemm1_clamp_limit / deep_gemm
+        # _apply_swiglu_limit). Plumbed into MOEConfig.swiglu_limit and
+        # consumed by amx::act_fn. Origin: kt-sglang 耦合.
+        swiglu_limit: float = 0.0,
     ):
         """
         Factory method to create the appropriate backend implementation.
@@ -213,8 +219,17 @@ class KTMoEWrapper:
                 max_deferred_experts_per_token=max_deferred_experts_per_token,
                 method=method,
                 numa_nodes=numa_nodes,
+                swiglu_limit=swiglu_limit,
             )
         else:  # mode == "sft"
+            # SFT factory does not plumb swiglu_limit; reject non-zero
+            # rather than dropping it on the floor. Origin: kt-sglang 耦合.
+            if swiglu_limit != 0.0:
+                raise ValueError(
+                    f"swiglu_limit={swiglu_limit} is not supported in "
+                    f"mode='sft' (method={method!r}); SFT backends do not "
+                    f"implement the V4-2604B clamp."
+                )
             return _create_sft_wrapper(
                 layer_idx=layer_idx,
                 num_experts=num_experts,
@@ -300,6 +315,7 @@ def _create_inference_wrapper(
     max_deferred_experts_per_token: Optional[int],
     method: str,
     numa_nodes: Optional[List[int]] = None,
+    swiglu_limit: float = 0.0,
 ) -> BaseMoEWrapper:
     """
     Create an inference wrapper based on the method.
@@ -323,7 +339,24 @@ def _create_inference_wrapper(
         # This shouldn't happen due to validation in __new__
         raise NotImplementedError(f"Unsupported inference method: {method}")
 
-    # Create and return backend instance
+    # Create and return backend instance.
+    # `swiglu_limit != 0` is meaningful only on the MXFP4 path. NativeMoEWrapper
+    # also serves RAWINT4 / FP8 / BF16 / FP8_PERCHANNEL / GPTQ_INT4, so a
+    # `backend_cls is NativeMoEWrapper` test would silently forward a stale
+    # 10.0 (e.g., from a leftover SGLANG_DSV4_2604_SUBMODE=2604B in the env)
+    # into a non-MXFP4 backend; act_fn would then clamp gate/up to ±10 with
+    # no warning. Gate strictly on method instead. Origin: kt-sglang 耦合.
+    extra_kwargs = {}
+    if method == "MXFP4":
+        extra_kwargs["swiglu_limit"] = swiglu_limit
+    elif swiglu_limit != 0.0:
+        raise ValueError(
+            f"swiglu_limit={swiglu_limit} is only supported on method='MXFP4', "
+            f"got method={method!r} (backend={backend_cls.__name__}). This "
+            f"usually means SGLANG_DSV4_2604_SUBMODE=2604B is set in the "
+            f"environment while the current launch does not actually use "
+            f"MXFP4 weights — either unset the env or pass --kt-method MXFP4."
+        )
     return backend_cls(
         layer_idx=layer_idx,
         num_experts=num_experts,
@@ -339,6 +372,7 @@ def _create_inference_wrapper(
         max_deferred_experts_per_token=max_deferred_experts_per_token,
         method=method,
         numa_nodes=numa_nodes,
+        **extra_kwargs,
     )