[Model] Switch to Fused RMSNorm in GLM-4.1V model (vllm-project#24733)

Signed-off-by: SamitHuang <[email protected]>

Author: SamitHuang

vllm/model_executor/models/glm4_1v.py

@@ -419,15 +419,16 @@ def forward(
             max_seqlen: Optional[int] = None,  # Only used for Flash Attention
             seqlens: Optional[list[int]] = None,  # Only used for xFormers
     ) -> torch.Tensor:
-        x = x + self.attn(
+        x_attn = self.attn(
             self.norm1(x),
             cu_seqlens=cu_seqlens,
             rotary_pos_emb=rotary_pos_emb,
             max_seqlen=max_seqlen,
             seqlens=seqlens,
         )
+        x_fused_norm, residual = self.norm2(x, residual=x_attn)
+        x = residual + self.mlp(x_fused_norm)
 
-        x = x + self.mlp(self.norm2(x))
         return x