add e2e tests for Unsloth qlora and test the builds (#2093)

* see if unsloth installs cleanly in ci

* check unsloth install on regular tests, not sdist

* fix ampere check exception for ci

* use cached_property instead

* add an e2e test for unsloth qlora

* reduce seq len and mbsz to prevent oom in ci

* add checks for fp16 and sdp_attention

* pin unsloth to a specific release

* add unsloth to docker image too

* fix flash attn xentropy patch

* fix loss, add check for loss when using fa_xentropy

* fix special tokens for test

* typo

* test fa xentropy with and without gradient accum

* pr feedback changes

src/axolotl/monkeypatch/llama_attn_hijack_flash.py

@@ -4,7 +4,6 @@
 
 import logging
 import warnings
-from functools import partial
 from typing import List, Optional, Tuple, Union
 
 import torch
@@ -94,13 +93,32 @@ def replace_llama_qkv_with_fused(model):
             set_module_name(model, name, qkv)
 
 
-def patch_llama_cross_entropy():
-    from flash_attn.losses.cross_entropy import CrossEntropyLoss
-
-    LOG.info("patching with flash_attn.losses.cross_entropy")
-    transformers.models.llama.modeling_llama.CrossEntropyLoss = partial(
-        CrossEntropyLoss, inplace_backward=True
+def patch_fa_llama_cross_entropy():
+    LOG.info(
+        "patching transformers.loss.loss_utils.fixed_cross_entropy with flash_attn.ops.triton.cross_entropy"
     )
+    from flash_attn.ops.triton.cross_entropy import (
+        cross_entropy_loss as flash_attn_cross_entropy_loss,
+    )
+
+    def fa2_fixed_cross_entropy(
+        source,
+        target,
+        num_items_in_batch: int = None,
+        ignore_index: int = -100,
+        **kwargs,
+    ):  # pylint: disable=unused-argument
+        reduction = "sum" if num_items_in_batch is not None else "mean"
+        loss, _ = flash_attn_cross_entropy_loss(
+            source, target, ignore_index=ignore_index
+        )
+        if reduction == "sum":
+            loss = loss.sum() / num_items_in_batch
+        else:
+            loss = loss.sum() / (target != ignore_index).sum()
+        return loss
+
+    transformers.loss.loss_utils.fixed_cross_entropy = fa2_fixed_cross_entropy
 
 
 def patch_llama_rms_norm():
@@ -147,7 +165,7 @@ def replace_llama_attn_with_flash_attn(
 
     # skip only if explicitly disabled
     if cross_entropy:
-        patch_llama_cross_entropy()
+        patch_fa_llama_cross_entropy()
 
     # skip only if explicitly disabled
     if rms_norm:

src/axolotl/utils/models.py

@@ -2,10 +2,12 @@
 
 # pylint: disable=too-many-lines
 import gc
+import importlib
 import logging
 import math
 import os
 import types
+from functools import cached_property
 from typing import Any, Dict, Optional, Tuple, Union  # noqa: F401
 
 import addict
@@ -409,7 +411,7 @@ class ModelLoader:
             )
 
             if self.cfg.is_llama_derived_model:
-                self.patch_loss()
+                self.patch_loss_llama()
                 if self.cfg.unsloth_lora_qkv or self.cfg.unsloth_lora_o:
                     from axolotl.monkeypatch.unsloth_ import patch_self_attn_lora
 
@@ -451,27 +453,34 @@ class ModelLoader:
 
                 replace_stablelm_attn_with_flash_attn(self.cfg.base_model)
 
-    def patch_loss(self) -> None:
+    @cached_property
+    def has_flash_attn(self) -> bool:
+        """Check if flash attention is installed"""
+        return importlib.util.find_spec("flash_attn") is not None
+
+    def patch_loss_llama(self) -> None:
         """
         Patch loss functions
         """
-        from axolotl.monkeypatch.llama_attn_hijack_flash import (
-            patch_llama_cross_entropy,
-            patch_llama_rms_norm,
-        )
+        if self.has_flash_attn:
+            from axolotl.monkeypatch.llama_attn_hijack_flash import (
+                patch_fa_llama_cross_entropy,
+                patch_llama_rms_norm,
+            )
 
-        if self.cfg.flash_attn_cross_entropy:
-            patch_llama_cross_entropy()
-        if self.cfg.flash_attn_rms_norm:
+        if self.cfg.flash_attn_cross_entropy and self.has_flash_attn:
+            patch_fa_llama_cross_entropy()
+        elif self.cfg.unsloth_cross_entropy_loss:
+            from axolotl.monkeypatch.unsloth_ import integrate_cross_entropy_loss_patch
+
+            integrate_cross_entropy_loss_patch(model_type="llama")
+
+        if self.cfg.flash_attn_rms_norm and self.has_flash_attn:
             patch_llama_rms_norm()
         elif self.cfg.unsloth_rms_norm:
             from axolotl.monkeypatch.unsloth_ import patch_unsloth_layernorm
 
             patch_unsloth_layernorm()
-        if self.cfg.unsloth_cross_entropy_loss:
-            from axolotl.monkeypatch.unsloth_ import integrate_cross_entropy_loss_patch
-
-            integrate_cross_entropy_loss_patch(model_type="llama")
         if self.cfg.unsloth_lora_qkv or self.cfg.unsloth_lora_o:
             from axolotl.monkeypatch.unsloth_ import patch_self_attn_lora
 
@@ -481,6 +490,7 @@ class ModelLoader:
         """
         Modify all llama derived models in one block
         """
+        self.patch_loss_llama()
 
         if self.cfg.flash_attention:
             from axolotl.monkeypatch.llama_attn_hijack_flash import (
@@ -528,16 +538,6 @@ class ModelLoader:
                 "Shifted-sparse attention not currently implemented without flash attention."
             )
 
-        if self.cfg.unsloth_cross_entropy_loss:
-            from axolotl.monkeypatch.unsloth_ import integrate_cross_entropy_loss_patch
-
-            integrate_cross_entropy_loss_patch(model_type="llama")
-
-        if self.cfg.unsloth_lora_qkv or self.cfg.unsloth_lora_o:
-            from axolotl.monkeypatch.unsloth_ import patch_self_attn_lora
-
-            patch_self_attn_lora()
-
     def set_auto_model_loader(self) -> None:
         """set self.AutoModelLoader
         - default value: AutoModelForCausalLM (set at __init__)