Refactor landmark attention patch

src/axolotl/monkeypatch/llama_landmark_attn.py

@@ -1593,3 +1593,12 @@ def add_mem_tokens(example, mem_freq, mem_id):
     ret.extend(x[prev_idx:])
     # drop attention_mask
     return {"input_ids": ret}
+
+
+def patch_llama_with_landmark_attn():
+    import transformers
+
+    transformers.models.llama.modeling_llama.LlamaForCausalLM = LlamaForCausalLM
+    transformers.models.llama.modeling_llama.LlamaModel = LlamaModel
+    transformers.models.llama.modeling_llama.LlamaAttention = LlamaAttention
+    transformers.models.llama.modeling_llama.LlamaDecoderLayer = LlamaDecoderLayer

src/axolotl/utils/models.py

@@ -19,15 +19,6 @@
     LlamaConfig,
 )
 
-try:
-    from transformers import (  # pylint: disable=unused-import  # noqa: F401
-        LlamaForCausalLM,
-    )
-except ImportError:
-    logging.warning(
-        "This version of transformers does not support Llama. Consider upgrading."
-    )
-
 from axolotl.prompt_tokenizers import LLAMA_DEFAULT_PAD_TOKEN
 
 if TYPE_CHECKING:
@@ -118,14 +109,15 @@ def load_model(
         logging.info("patching with sdp attention")
         hijack_llama_sdp_attention()
     elif cfg.is_llama_derived_model and cfg.landmark_attention:
-        from axolotl.monkeypatch.llama_landmark_attn import (  # pylint: disable=redefined-outer-name # noqa: F811
+        from axolotl.monkeypatch.llama_landmark_attn import (
             MEM_TOKEN,
-            LlamaForCausalLM,
+            patch_llama_with_landmark_attn,
         )
 
         logging.info("patching with landmark attention")
+        patch_llama_with_landmark_attn()
 
-        # TODO: Check if this would overwrite previous additional_special_tokens
+        # Note: This might overwrite previous additional_special_tokens
         tokenizer.add_special_tokens({"additional_special_tokens": [MEM_TOKEN]})
 
     if cfg.is_llama_derived_model and cfg.xpos_rope:
@@ -211,6 +203,13 @@ def load_model(
             )
             load_in_8bit = False
         elif cfg.is_llama_derived_model and "LlamaForCausalLM" in globals():
+            try:
+                from transformers import LlamaForCausalLM
+            except ImportError:
+                logging.warning(
+                    "This version of transformers does not support Llama. Consider upgrading."
+                )
+
             config = LlamaConfig.from_pretrained(base_model_config)
             model = LlamaForCausalLM.from_pretrained(
                 base_model,