batch flattening with xformers too

src/axolotl/utils/schemas/config.py

@@ -475,8 +475,14 @@ class AxolotlInputConfig(
     def check_batch_flattening_fa(cls, data):
         if data.get("batch_flattening"):
             batch_flattening_auto = data.get("batch_flattening") == "auto"
-            if not data.get("flash_attention") and not batch_flattening_auto:
-                raise ValueError("batch_flattening requires flash attention")
+            if (
+                not data.get("flash_attention")
+                and not data.get("xformers_attention")
+                and not batch_flattening_auto
+            ):
+                raise ValueError(
+                    "batch_flattening requires flash attention or xformers"
+                )
             if data.get("sample_packing") and not batch_flattening_auto:
                 raise ValueError("batch_flattening not compatible with sample_packing")
             if data.get("micro_batch_size") == 1 and not batch_flattening_auto: