ungate lora with bias

docs/lora_optims.qmd

@@ -5,10 +5,11 @@ description: "Custom autograd functions and Triton kernels in Axolotl for optimi
 
 Inspired by [Unsloth](https://github.com/unslothai/unsloth), we've implemented two
 optimizations for LoRA and QLoRA fine-tuning, supporting both single GPU and multi-GPU
-(in the DDP and DeepSpeed settings) training. These include (1) SwiGLU and GEGLU activation function
-Triton kernels, and (2) LoRA MLP and attention custom autograd functions. Our goal was
-to leverage operator fusion and tensor re-use in order to improve speed and reduce
-memory usage during the forward and backward passes of these calculations.
+(including DDP, DeepSpeed, and FSDP2) training. These include (1) SwiGLU and GEGLU
+activation function Triton kernels, and (2) LoRA MLP and attention custom autograd
+functions. Our goal was to leverage operator fusion and tensor re-use in order to
+improve speed and reduce memory usage during the forward and backward passes of these
+calculations.
 
 We currently support several common model architectures, including (but not limited to):
 
@@ -92,13 +93,12 @@ Currently, LoRA kernels are not supported for RLHF training, only SFT.
 
 - One or more NVIDIA or AMD GPUs (in order to use the Triton kernels)
     - Note: Set `TORCH_ROCM_AOTRITON_ENABLE_EXPERIMENTAL=1` to enable [memory-efficient attention on AMD GPUs](https://github.com/ROCm/aotriton/issues/16#issuecomment-2346675491)
-- Targeted LoRA adapters cannot use Dropout
-    - This may limit model expressivity / cause overfitting
-- Targeted LoRA adapters cannot have bias terms
+- Targeted LoRA adapters must disable dropout (`lora_dropout: 0`)
     - This may limit model expressivity
+- Adapters that already include bias terms are supported.
 
-Models with pre-existing LoRA adapters that use Dropout or have bias terms may need to
-be re-finetuned without these features in order to be useful.
+Models with pre-existing LoRA adapters that use Dropout may need to be re-finetuned
+without it in order to be as performant.
 
 ## Implementation details
 
@@ -131,6 +131,5 @@ computation path.
 ## Future Work
 
 - Support for additional model architectures
-- Support for the FSDP setting
-- Support for dropout and bias
+- Support for dropout
 - Additional operator fusions

src/axolotl/monkeypatch/lora_kernels.py

@@ -323,8 +323,8 @@ def apply_lora_kernel_patches(
         AssertionError: If multiple adapters are active (currently unsupported).
 
     Note:
-        The optimizations require LoRA adapters with no dropout and no bias terms. The
-            function will skip patching if these conditions aren't met.
+        The optimizations require LoRA adapters with no dropout. The function will skip
+        patching if that condition isn't met.
     """
     if not isinstance(model, PeftModelForCausalLM):
         raise TypeError("Model must be a PeftModelForCausalLM")
@@ -340,10 +340,10 @@ def apply_lora_kernel_patches(
     lora_config = model.model.peft_config[active_adapter]
 
     # Only patch if conditions are met
-    can_patch = lora_config.lora_dropout == 0 and lora_config.bias == "none"
+    can_patch = lora_config.lora_dropout == 0
 
     if not can_patch:
-        LOG.warning("Cannot patch layers - requires no dropout and no bias")
+        LOG.warning("Cannot patch layers - requires `lora_dropout: 0`")
         LOG.warning("Please specify `lora_dropout: 0` in your axolotl config file")
         return model
 

tests/e2e/patched/lora_kernels/test_lora_kernel_patching.py

@@ -221,44 +221,53 @@ def test_model_specific_activation(model_name, expected_activation):
     assert layer.mlp.forward.__func__ is expected_activation
 
 
-def test_kernel_patch_conditions():
-    """Test various conditions that should prevent kernel patching."""
-    test_configs = [
-        # Dropout prevents patching
-        {
-            "peft_type": "LORA",
-            "task_type": "CAUSAL_LM",
-            "r": 8,
-            "lora_alpha": 16,
-            "target_modules": ["gate_proj", "up_proj", "down_proj"],
-            "lora_dropout": 0.1,
-            "bias": "none",
-        },
-        # Bias prevents patching
-        {
-            "peft_type": "LORA",
-            "task_type": "CAUSAL_LM",
-            "r": 8,
-            "lora_alpha": 16,
-            "target_modules": ["gate_proj", "up_proj", "down_proj"],
-            "lora_dropout": 0,
-            "bias": "lora_only",
-        },
-    ]
+def test_kernel_patch_requires_zero_dropout():
+    """Kernel patching should be skipped when dropout is enabled."""
+    config = {
+        "peft_type": "LORA",
+        "task_type": "CAUSAL_LM",
+        "r": 8,
+        "lora_alpha": 16,
+        "target_modules": ["gate_proj", "up_proj", "down_proj"],
+        "lora_dropout": 0.1,
+        "bias": "none",
+    }
 
-    for config in test_configs:
-        model = AutoModelForCausalLM.from_pretrained("HuggingFaceTB/SmolLM2-135M")
-        peft_config = get_peft_config(config)
-        model = PeftModelForCausalLM(model, peft_config)
-        cfg = DictDefault({"lora_mlp_kernel": True})
+    model = AutoModelForCausalLM.from_pretrained("HuggingFaceTB/SmolLM2-135M")
+    peft_config = get_peft_config(config)
+    model = PeftModelForCausalLM(model, peft_config)
+    cfg = DictDefault({"lora_mlp_kernel": True})
 
-        # Should not patch
-        patched_model = apply_lora_kernel_patches(model, cfg)
-        layer = patched_model.model.model.layers[0].mlp
+    patched_model = apply_lora_kernel_patches(model, cfg)
+    layer = patched_model.model.model.layers[0].mlp
 
-        # Verify no patches applied
-        assert layer.forward.__func__ is not apply_lora_mlp_swiglu
-        assert layer.forward.__func__ is not apply_lora_mlp_geglu
+    # Verify no patches applied when dropout is non-zero
+    assert layer.forward.__func__ is not apply_lora_mlp_swiglu
+    assert layer.forward.__func__ is not apply_lora_mlp_geglu
+
+
+def test_kernel_patch_with_bias_enabled():
+    """Kernel patching should succeed when LoRA bias is enabled."""
+    config = {
+        "peft_type": "LORA",
+        "task_type": "CAUSAL_LM",
+        "r": 8,
+        "lora_alpha": 16,
+        "target_modules": ["gate_proj", "up_proj", "down_proj"],
+        "lora_dropout": 0,
+        "bias": "lora_only",
+    }
+
+    model = AutoModelForCausalLM.from_pretrained("HuggingFaceTB/SmolLM2-135M")
+    peft_config = get_peft_config(config)
+    model = PeftModelForCausalLM(model, peft_config)
+    cfg = DictDefault({"lora_mlp_kernel": True})
+
+    patched_model = apply_lora_kernel_patches(model, cfg)
+    layer = patched_model.model.model.layers[0].mlp
+
+    # Verify patches applied when bias support is enabled
+    assert layer.forward.__func__ is apply_lora_mlp_swiglu
 
 
 def test_kernel_config_options():