Files
axolotl/examples/ebft/llama-1b-ebft-opencode.yaml
Wing Lian e4032fc90f Refactor separate attention flags with attn_implementation and capability/concerns feature flags (#3602)
* upgrade to torchao 0.17.0

* chore: lint

* refactor attention handling

* replace legacy attention boolean flags with capability properties

Replace checks with capability-based properties derived from attn_implementation

This separates three concerns that were conflated under flash_attention:
1. Backend selection -> attn_implementation enum
2. Packing capability -> attn_supports_packing property
3. Flash-attn library dependency -> attn_uses_flash_lib property

* compute attn capability flags in normalizer instead of properties

* make attn_implementation the single source of truth

* move attention-dependent validators to mode=after

* migrate remaining consumers to canonical attn_implementation

* expand attention tests + rewrite docs

* migrate example configs to canonical attn_implementation

* update doc snippets + reject gemma4-hybrid with non-FA2 backend

* remove dead gemma4 branch in _set_attention_config

* fix duplicate attn_implementation in gpt-oss yamls and flaky caplog tests

* drop "Phase 2" naming from attn-implementation tests

* regroup attn_implementation tests by feature concern

* clean up verbose comments and remove MD

Signed-off-by: Wing Lian <wing@axolotl.ai>
Co-authored-by: Axolotl Swarm <no-reply@axolotl.ai>

* fix(collator): pass return_dict=True at apply_chat_template top level for transformers 5.x

In transformers 5.x, ProcessorMixin.apply_chat_template gained its own
`return_dict` parameter (defaulting to False).  When return_dict=False
and tokenize=True the method returns out["input_ids"] directly — a 2-D
tensor — rather than the full BatchFeature dict.

The old code placed `return_dict=True` inside processor_kwargs.  In
transformers 5.x those kwargs are forwarded to the underlying processor
call self(...) where _merge_kwargs silently ignores any key not present
in MllamaProcessorKwargs (emitting a warning).  The outer return_dict
therefore stayed False, apply_chat_template returned the raw input_ids
tensor, and the subsequent `batch["input_ids"]` attempted to index a
2-D tensor with the 9-character string "input_ids", producing:

  IndexError: too many indices for tensor of dimension 2

The fix is to pass return_dict=True as a top-level keyword argument to
apply_chat_template (where it is actually consumed) and remove it from
processor_kwargs (where it was silently dropped).  No version guard is
needed: transformers is pinned to ==5.5.4 in pyproject.toml.

Adds a unit-level regression test (tests/test_mm_chat_collator.py) that
mocks the processor to return a raw tensor when apply_chat_template is
called without top-level return_dict=True, verifying the four invariants:
process_rows returns a dict, input_ids is 2-D, labels is 2-D, and
apply_chat_template receives return_dict=True as a top-level kwarg.

Fixes: tests/e2e/test_llama_vision.py::TestLlamaVision::test_lora_llama_vision_multimodal_dataset
Fixes: tests/e2e/test_llama_vision.py::TestLlamaVision::test_lora_llama_vision_text_only_dataset
Signed-off-by: Wing Lian <wing@axolotl.ai>
Co-authored-by: Axolotl Swarm <no-reply@axolotl.ai>

* fix(collator): process_rows returns dict (BatchFeature) shape

Two related changes for the multimodal chat collator under transformers 5.x:

1. Wrap apply_chat_template result in dict(...) so process_rows returns
   a plain dict rather than a BatchFeature instance. BatchFeature is a
   Mapping but not a dict; downstream code that did
     batch["labels"] = self.processing_strategy.process_labels(batch["input_ids"])
   would index on a tensor when the result wasn't dict-shaped, raising
     IndexError: too many indices for tensor of dimension 2

2. Soften the regression test's contract from `dict` to `Mapping` so it
   exercises the actual semantic guarantee (key/value access) rather
   than the implementation detail (dict vs BatchFeature). Test guards
   against the original transformers 5.x breakage where apply_chat_template's
   return_dict default went from True to False.

Includes regression test under tests/test_mm_chat_collator.py.

Bug surfaced via swarm dispatch task_01KQHPNAYD8XARSNSDJVW1GPF6 against
attn-implementation-refactor; squash-merged from agent commits 4de886fd
+ dc9fcf4f.

Signed-off-by: Wing Lian <wing@axolotl.ai>

---------

Signed-off-by: Wing Lian <wing@axolotl.ai>
Co-authored-by: Axolotl Swarm <no-reply@axolotl.ai>
2026-05-05 10:15:18 -04:00

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2.3 KiB
YAML

# EBFT: Energy-Based Fine-Tuning with Llama-3.2-1B on OpenCodeInstruct
#
# Paper: "Matching Features, Not Tokens" (Jelassi et al., 2026)
# https://arxiv.org/abs/2603.12248
#
# Prerequisites:
# 1. Start vLLM server on a separate GPU:
# CUDA_VISIBLE_DEVICES=1 python -m trl.scripts.vllm_serve \
# --model meta-llama/Llama-3.2-1B \
# --host 0.0.0.0 --port 8000 \
# --gpu-memory-utilization 0.4 --dtype bfloat16
#
# 2. Run training:
# CUDA_VISIBLE_DEVICES=0 axolotl train examples/ebft/llama-1b-ebft-opencode.yaml
base_model: meta-llama/Llama-3.2-1B
chat_template: llama3
# --- Training method ---
rl: ebft
# --- EBFT configuration ---
ebft:
feature_layers: [0.25, 0.5, 0.75] # extract hidden states at 25%, 50%, 75% depth
embed_method: last_token # pool to sequence embedding via last token
use_whitening: false # SVD whitening (disable for speed in small runs)
alignment_coef: 1.0 # cosine similarity with ground-truth features
diversity_coef: 1.0 # pairwise similarity penalty
ce_coef: 0.0 # cross-entropy on ground-truth (0 = pure feature matching)
# --- Generation settings (via TRL/GRPO infrastructure) ---
trl:
num_generations: 4 # samples per prompt for RLOO
max_completion_length: 256 # max generated tokens
temperature: 1.0
use_vllm: true
scale_rewards: true
loss_type: grpo
epsilon: 0.2
# --- Dataset ---
datasets:
- path: nvidia/OpenCodeInstruct
type: ebft_opencode.transform
split: train[:1%] # first 1% for validation runs
# --- Training hyperparameters ---
sequence_len: 1024
micro_batch_size: 2
gradient_accumulation_steps: 4
num_epochs: 1
max_steps: 50
learning_rate: 1.0e-5
optimizer: adamw_torch_fused
lr_scheduler: cosine
warmup_steps: 5
weight_decay: 0.01
# --- LoRA (recommended to reduce memory with frozen feature network) ---
adapter: lora
lora_r: 16
lora_alpha: 32
lora_dropout: 0.05
lora_target_linear: true
# --- Hardware ---
bf16: auto
attn_implementation: flash_attention_2
gradient_checkpointing: true
special_tokens:
pad_token: "<|end_of_text|>"
val_set_size: 0.0
output_dir: ./outputs/ebft-llama-1b-opencode
# --- Logging ---
use_tensorboard: true
logging_steps: 1
save_steps: 25