[1/2] Support deterministic inference with flashinfer attention backend (#10645)

Co-authored-by: hebiao064 <hebiaobuaa@gmail.com>
Co-authored-by: Qiaolin-Yu <liin1211@outlook.com>

python/sglang/srt/layers/layernorm.py

@@ -14,6 +14,7 @@
 """Fused operators for normalization layers."""
 
 import logging
+import os
 from typing import Optional, Tuple, Union
 
 import torch
@@ -80,6 +81,8 @@ class RMSNorm(CustomOp):
         )
         if _use_aiter:
             self._forward_method = self.forward_aiter
+        if os.environ["SGLANG_ENABLE_DETERMINISTIC_INFERENCE"] == "1":
+            self._forward_method = self.forward_native
 
     def forward_cuda(
         self,