[smol] [perf] Qwen3-VL in place op. (#11481)

Signed-off-by: vincentzed <207368749+vincentzed@users.noreply.github.com>

python/sglang/srt/models/qwen3_vl.py

@@ -189,10 +189,10 @@ class Qwen3_VisionBlock(nn.Module):
             position_embeddings=position_embeddings,
         )
         attn = rearrange(attn, "b s ... -> s b ...")
-        x = x + attn
+        x += attn
         norm2 = self.norm2(x)
         mlp = self.mlp(norm2)
-        x = x + mlp
+        x += mlp
         return x
 
 
@@ -441,7 +441,7 @@ class Qwen3_VisionTransformer(nn.Module):
         x = self.patch_embed(x)
 
         pos_embeds = self.fast_pos_embed_interpolate(grid_thw)
-        x = x + pos_embeds
+        x += pos_embeds
         rotary_pos_emb = self.rot_pos_emb(grid_thw)
 
         seq_len, _ = x.size()
@@ -574,10 +574,7 @@ class Qwen3LLMModel(Qwen3Model):
                 and layer_idx in self.deepstack_embed_to_decoder_layer
             ):
                 sep = self.hidden_size * layer_idx
-                hidden_states = (
+                hidden_states += input_deepstack_embeds[:, sep : sep + self.hidden_size]
-                    hidden_states
-                    + input_deepstack_embeds[:, sep : sep + self.hidden_size]
-                )
 
         if not self.pp_group.is_last_rank:
             return PPProxyTensors(

python/sglang/srt/models/qwen3_vl_moe.py

@@ -114,7 +114,7 @@ class Qwen3MoeLLMModel(Qwen3MoeModel):
         for layer_idx, layer in enumerate(
             self.layers[self.start_layer : self.end_layer]
         ):
-            layer_idx = layer_idx + self.start_layer
+            layer_idx += self.start_layer
             if layer_idx in self.layers_to_capture:
                 aux_hidden_states.append(
                     hidden_states + residual if residual is not None else hidden_states
@@ -130,9 +130,8 @@ class Qwen3MoeLLMModel(Qwen3MoeModel):
             # process deepstack
             if input_deepstack_embeds is not None and layer_idx in range(3):
                 sep = self.hidden_size * layer_idx
-                hidden_states = (
+                hidden_states.add_(
-                    hidden_states
+                    input_deepstack_embeds[:, sep : sep + self.hidden_size]
-                    + input_deepstack_embeds[:, sep : sep + self.hidden_size]
                 )
 
         if not self.pp_group.is_last_rank: