changes

src/axolotl/cli/integrations/convert_diff_transformer.py

@@ -18,6 +18,7 @@ from axolotl.common.cli import ConvertDiffTransformerCliArgs, load_model_and_tok
 from axolotl.integrations.diff_transformer.modeling_diff_attn import (
     LlamaDifferentialConfig,
     LlamaDifferentialForCausalLM,
+    register_diff_attn,
 )
 from axolotl.utils.yaml import dump_yaml_preserved_order
 
@@ -50,6 +51,7 @@ def test_inference(model, tokenizer, prompt="The quick brown fox"):
 
 
 def convert_diff_transformer(cfg, cli_args, config_path):
+    register_diff_attn()
     debug_info = {}
 
     # Load model and tokenizer
@@ -82,15 +84,13 @@ def convert_diff_transformer(cfg, cli_args, config_path):
             + Fore.RESET
         )
     try:
-        model = LlamaDifferentialForCausalLM.from_llama(
-            model,
-            LlamaDifferentialConfig(
-                **model.config.__dict__,
-                zero_init=cli_args.zero_init,
-                sublayer_norm=cli_args.sublayer_norm,
-                split_heads=cli_args.split_heads,
-            ),
+        config = LlamaDifferentialConfig(
+            **model.config.__dict__,
+            zero_init=cli_args.zero_init,
+            sublayer_norm=cli_args.sublayer_norm,
+            split_heads=cli_args.split_heads,
         )
+        model = LlamaDifferentialForCausalLM.from_llama(model, config)
         model.to(cfg.device, dtype=cfg.torch_dtype)
     except Exception as exc:
         LOG.error(Fore.RED + "Conversion failed: %s" + Fore.RESET, str(exc))

src/axolotl/integrations/diff_transformer/modeling_diff_attn.py

@@ -1,6 +1,7 @@
 """Modeling for differential transformers."""
 
-from typing import Optional
+import logging
+from typing import Optional, Union
 
 import torch
 from transformers import AutoConfig, AutoModel, AutoModelForCausalLM
@@ -18,6 +19,8 @@ from .diff_attn import (
     LlamaDifferentialSdpaAttention,
 )
 
+logger = logging.getLogger(__name__)
+
 
 class LlamaDifferentialConfig(LlamaConfig):
     """Configuration class for Differential LLaMA model."""
@@ -55,26 +58,85 @@ class LlamaDifferentialPreTrainedModel(LlamaPreTrainedModel):
 class LlamaDifferentialModel(LlamaModel):
     """LlamaModel with differential attention."""
 
+    config_class = LlamaDifferentialConfig
+    base_model_prefix = "llama_differential"
+
     def __init__(self, config):
         super().__init__(config)
 
+        # Handle attention implementation
+        attn_impl = config._attn_implementation or "eager"
+        if attn_impl in config._attn_implementations:
+            attn_impl = config._attn_implementations[attn_impl]
+
+        # Validate attention implementation
+        valid_impls = [
+            None,
+            "differential_eager",
+            "differential_sdpa",
+            "differential_flash_attention_2",
+        ]
+        if attn_impl not in valid_impls:
+            raise ValueError(f"Invalid attention implementation: {attn_impl}")
+
         # Replace standard attention with differential attention in each layer
+        attn_classes = {
+            "differential_eager": LlamaDifferentialAttention,
+            "differential_sdpa": LlamaDifferentialSdpaAttention,
+            "differential_flash_attention_2": LlamaDifferentialFlashAttention2,
+        }
+        attn_class = attn_classes.get(attn_impl, LlamaDifferentialAttention)
+
         for idx, layer in enumerate(self.layers):
-            attn_impl = config._attn_implementation or "eager"
-            if attn_impl == "eager":
-                layer.self_attn = LlamaDifferentialAttention(config, idx)
-            elif attn_impl == "sdpa":
-                layer.self_attn = LlamaDifferentialSdpaAttention(config, idx)
-            elif attn_impl == "flash_attention_2":
-                layer.self_attn = LlamaDifferentialFlashAttention2(config, idx)
+            layer.self_attn = attn_class(config, idx)
+
+    # pylint: disable=protected-access
+    @classmethod
+    def _autoset_attn_implementation(
+        cls, config, **kwargs
+    ):  # pylint: disable=unused-argument
+        config._attn_implementation_autoset = True
+        attn_implementation = getattr(config, "_attn_implementation", None)
+
+        # Map standard types to differential types if mapping exists
+        if attn_implementation in config._attn_implementations:
+            config._attn_implementation = config._attn_implementations[
+                attn_implementation
+            ]
+            return config
+
+        # If no mapping, validate it's a valid differential type
+        valid_impls = [
+            None,
+            "differential_eager",
+            "differential_sdpa",
+            "differential_flash_attention_2",
+        ]
+        if attn_implementation not in valid_impls:
+            message = (
+                f"Specified `attn_implementation={attn_implementation}` is not supported. "
+                f"The only possible arguments are: {', '.join(repr(x) for x in valid_impls if x)}"
+            )
+            raise ValueError(message)
+
+        return config
 
     @classmethod
     def from_llama(
-        cls, model: LlamaModel, config: Optional[LlamaDifferentialConfig] = None
+        cls,
+        model: Union[LlamaModel, LlamaForCausalLM],
+        config: Optional[LlamaDifferentialConfig] = None,
     ) -> "LlamaDifferentialModel":
         """Convert a LlamaModel to use differential attention."""
+        logger.info(f"Converting {type(model).__name__} to {cls.__name__}")
+
+        # Handle LlamaForCausalLM
+        if isinstance(model, LlamaForCausalLM):
+            model = model.model
+
         if config is None:
             config = LlamaDifferentialConfig(**model.config.__dict__)
+            logger.debug(f"Created config: {config}")
 
         # Validate head counts if using split heads mode
         if config.split_heads:
@@ -92,10 +154,14 @@ class LlamaDifferentialModel(LlamaModel):
         new_model = cls(config)
 
         # Copy all weights except attention
+        logger.debug("Copying embeddings and norm")
         new_model.embed_tokens.load_state_dict(model.embed_tokens.state_dict())
         new_model.norm.load_state_dict(model.norm.state_dict())
 
-        for new_layer, old_layer in zip(new_model.layers, model.layers):
+        logger.debug("Copying layer weights")
+        for layer_idx, (new_layer, old_layer) in enumerate(
+            zip(new_model.layers, model.layers)
+        ):
             # Copy everything except attention weights
             new_layer.mlp.load_state_dict(old_layer.mlp.state_dict())
             new_layer.input_layernorm.load_state_dict(
@@ -109,7 +175,6 @@ class LlamaDifferentialModel(LlamaModel):
             new_layer.self_attn.v_proj.load_state_dict(
                 old_layer.self_attn.v_proj.state_dict()
             )
-            print(old_layer.self_attn.o_proj.weight.shape)
             new_layer.self_attn.o_proj.load_state_dict(
                 old_layer.self_attn.o_proj.state_dict()
             )
@@ -119,6 +184,9 @@ class LlamaDifferentialModel(LlamaModel):
             old_k_size = old_layer.self_attn.k_proj.weight.size(0)
 
             if not config.split_heads:
+                logger.debug(
+                    f"Layer {layer_idx}: Copying Q/K projections with sizes {old_q_size}, {old_k_size}"
+                )
                 new_layer.self_attn.q_proj.weight.data[:old_q_size].copy_(
                     old_layer.self_attn.q_proj.weight.data
                 )
@@ -127,6 +195,7 @@ class LlamaDifferentialModel(LlamaModel):
                 )
 
                 if config.zero_init:
+                    logger.debug(f"Layer {layer_idx}: Zero initializing")
                     # Zero out components as needed
                     with torch.no_grad():
                         new_layer.self_attn.q_proj.weight.data[old_q_size:].zero_()
@@ -137,6 +206,7 @@ class LlamaDifferentialModel(LlamaModel):
                         new_layer.self_attn.lambda_k2.zero_()
                         new_layer.self_attn.lambda_init.zero_()
 
+        logger.info("Conversion complete")
         return new_model