Fix reward/classification models broken by load_weights v2 dispatch (#28671) (#31988)

Co-authored-by: Alex Nails <alex.nails@radixark.ai>

python/sglang/srt/models/llama_classification.py

@@ -83,7 +83,7 @@ class LlamaForClassification(nn.Module):
             elif "lm_head" in name:
                 continue
             else:
-                LlamaForCausalLM.load_weights(self, [(name, loaded_weight)])
+                LlamaForCausalLM._legacy_load_weights(self, [(name, loaded_weight)])
 
 
 EntryClass = LlamaForClassification

python/sglang/srt/models/llama_reward.py

@@ -74,7 +74,7 @@ class LlamaForSequenceClassification(nn.Module):
         )
 
     def load_weights(self, weights: Iterable[Tuple[str, torch.Tensor]]):
-        return LlamaForCausalLM.load_weights(self, weights)
+        return LlamaForCausalLM._legacy_load_weights(self, weights)
 
 
 class LlamaForSequenceClassificationWithNormal_Weights(LlamaForSequenceClassification):

python/sglang/srt/models/qwen2_classification.py

@@ -71,7 +71,7 @@ class Qwen2ForSequenceClassification(nn.Module):
         filtered_weights = [
             (name, w) for name, w in weights if not name.startswith("lm_head")
         ]
-        return Qwen2ForCausalLM.load_weights(self, filtered_weights)
+        return Qwen2ForCausalLM._legacy_load_weights(self, filtered_weights)
 
 
 EntryClass = [

python/sglang/srt/models/qwen2_rm.py

@@ -84,7 +84,7 @@ class Qwen2ForRewardModel(nn.Module):
         filtered_weights = [
             (name, w) for name, w in weights if not name.startswith("lm_head")
         ]
-        return Qwen2ForCausalLM.load_weights(self, filtered_weights)
+        return Qwen2ForCausalLM._legacy_load_weights(self, filtered_weights)
 
 
 EntryClass = [