Fix dpsk-r1-fp4 tp8 by reverting two commits (#13162 and #13341) (#13348)

Co-authored-by: Kangyan-Zhou <zky314343421@gmail.com>

python/sglang/srt/eplb/expert_location.py

@@ -284,17 +284,9 @@ class ExpertLocationMetadata:
     # -------------------------------- usage ------------------------------------
 
     def logical_to_all_physical(
-        self,
-        layer_id: int,
-        logical_expert_id: int,
-        require_global_experts: bool = False,
+        self, layer_id: int, logical_expert_id: int
     ) -> List[int]:
         # Use CPU copy to avoid GPU→CPU sync on every call, which is expensive in update weights scenario
-        if require_global_experts:
-            num_physical_experts = self.logical_to_all_physical_map_cpu[layer_id].shape[
-                -1
-            ]
-            return list(torch.arange(0, num_physical_experts))
         return [
             physical_expert_id
             for physical_expert_id in self.logical_to_all_physical_map_cpu[
@@ -363,10 +355,14 @@ def _compute_logical_to_all_physical_map(
                 )
 
                 # Replace by the nearest physical expert
-                if nearest_expert != -1:
-                    logical_to_all_physical_map[layer_id][logical_expert_id] = [
-                        nearest_expert
-                    ]
+                mapped_physical_experts = logical_to_all_physical_map[layer_id][
+                    logical_expert_id
+                ]
+                if (
+                    nearest_expert != -1
+                    and nearest_expert not in mapped_physical_experts
+                ):
+                    mapped_physical_experts[0] = nearest_expert
 
     logical_to_all_physical_map = _pad_nested_array(
         logical_to_all_physical_map, pad_value=-1