Fix MiniMax-M2 rmsnorm precision and remove useless code (#27627)

Signed-off-by: xuebi <xuebi@minimaxi.com>
Co-authored-by: xuebi <xuebi@minimaxi.com>

vllm/model_executor/layers/mamba/linear_attn.py

@@ -77,7 +77,7 @@ class MiniMaxText01RMSNormTP(CustomOp):
         if self.tp_world > 1:
             variance = tensor_model_parallel_all_reduce(variance) / self.tp_world
         x = x * torch.rsqrt(variance + self.variance_epsilon)
-        x = x.to(orig_dtype) * self.weight
+        x = (x * self.weight).to(orig_dtype)
         return x
 
     def forward(

vllm/model_executor/models/minimax_m2.py

@@ -263,23 +263,6 @@ class MiniMaxM2DecoderLayer(nn.Module):
         # with the layer's index.
         layer_idx = int(prefix.split(sep=".")[-1])
 
-        # TODO: support MTP
-        attn_window_size = getattr(config, "attn_window_size", None)
-        if attn_window_size is not None:
-            if isinstance(attn_window_size, list):
-                attn_window_size = attn_window_size[layer_idx]
-            elif isinstance(attn_window_size, int):
-                attn_window_size = attn_window_size
-            else:
-                raise ValueError(f"Invalid attn_window_size: {attn_window_size}")
-            attn_window_size = None if attn_window_size <= 0 else attn_window_size
-
-        # different rope theta for full layer and swa layer
-        swa_rope_theta = getattr(config, "swa_rope_theta", -1)
-        # default to full rope theta
-        swa_rope_theta = rope_theta if swa_rope_theta <= 0 else swa_rope_theta
-        rope_theta = swa_rope_theta if attn_window_size is not None else rope_theta
-
         self.layer_idx = layer_idx
         self.self_attn = MiniMaxM2Attention(
             hidden_size=self.hidden_size,
@@ -288,7 +271,6 @@ class MiniMaxM2DecoderLayer(nn.Module):
             rotary_dim=config.rotary_dim,
             rope_theta=rope_theta,
             rope_scaling=rope_scaling,
-            attn_window_size=attn_window_size,
             max_position_embeddings=max_position_embeddings,
             rms_norm_eps=config.rms_norm_eps,
             qkv_bias=getattr(config, "attention_bias", False),