llama-recipes/recipes/finetuning

Finetuning Llama

This folder contains instructions to fine-tune Llama 2 on a

• single-GPU setup
• multi-GPU setup

using the canonical finetuning script in the llama-recipes package.

If you are new to fine-tuning techniques, check out an overview: [](./LLM_finetuning_overview.md)

[!TIP] If you want to try finetuning Llama 2 with Huggingface's trainer, here is a Jupyter notebook with an example

How to configure finetuning settings?

[!TIP] All the setting defined in config files can be passed as args through CLI when running the script, there is no need to change from config files directly.

• Training config file is the main config file that helps to specify the settings for our run and can be found in configs folder

It lets us specify the training settings for everything from model_name to dataset_name, batch_size and so on. Below is the list of supported settings:

model_name: str="PATH/to/LLAMA 2/7B"
enable_fsdp: bool= False
run_validation: bool=True
batch_size_training: int=4
gradient_accumulation_steps: int=1
num_epochs: int=3
num_workers_dataloader: int=2
lr: float=2e-4
weight_decay: float=0.0
gamma: float= 0.85
use_fp16: bool=False
mixed_precision: bool=True
val_batch_size: int=4
dataset = "samsum_dataset" # alpaca_dataset, grammar_dataset
peft_method: str = "lora" # None , llama_adapter, prefix
use_peft: bool=False
output_dir: str = "./ft-output"
freeze_layers: bool = False
num_freeze_layers: int = 1
quantization: bool = False
save_model: bool = False
dist_checkpoint_root_folder: str="model_checkpoints"
dist_checkpoint_folder: str="fine-tuned"
save_optimizer: bool=False

• Datasets config file provides the available options for datasets.

• peft config file provides the supported PEFT methods and respective settings that can be modified.

• FSDP config file provides FSDP settings such as:

  • mixed_precision boolean flag to specify using mixed precision, defatults to true.

  • use_fp16 boolean flag to specify using FP16 for mixed precision, defatults to False. We recommond not setting this flag, and only set mixed_precision that will use BF16, this will help with speed and memory savings while avoiding challenges of scaler accuracies with FP16.

  • sharding_strategy this specifies the sharding strategy for FSDP, it can be:

    • FULL_SHARD that shards model parameters, gradients and optimizer states, results in the most memory savings.

    • SHARD_GRAD_OP that shards gradinets and optimizer states and keeps the parameters after the first all_gather. This reduces communication overhead specially if you are using slower networks more specifically beneficial on multi-node cases. This comes with the trade off of higher memory consumption.

    • NO_SHARD this is equivalent to DDP, does not shard model parameters, gradinets or optimizer states. It keeps the full parameter after the first all_gather.

    • HYBRID_SHARD available on PyTorch Nightlies. It does FSDP within a node and DDP between nodes. It's for multi-node cases and helpful for slower networks, given your model will fit into one node.

• checkpoint_type specifies the state dict checkpoint type for saving the model. FULL_STATE_DICT streams state_dict of each model shard from a rank to CPU and assembels the full state_dict on CPU. SHARDED_STATE_DICT saves one checkpoint per rank, and enables the re-loading the model in a different world size.

• fsdp_activation_checkpointing enables activation checkpoining for FSDP, this saves significant amount of memory with the trade off of recomputing itermediate activations during the backward pass. The saved memory can be re-invested in higher batch sizes to increase the throughput. We recommond you use this option.

• pure_bf16 it moves the model to BFloat16 and if optimizer is set to anyprecision then optimizer states will be kept in BFloat16 as well. You can use this option if necessary.

Weights & Biases Experiment Tracking

You can enable W&B experiment tracking by using use_wandb flag as below. You can change the project name, entity and other wandb.init arguments in wandb_config.

python -m llama_recipes.finetuning --use_peft --peft_method lora --quantization --model_name /patht_of_model_folder/7B --output_dir Path/to/save/PEFT/model --use_wandb

You'll be able to access a dedicated project or run link on wandb.ai and see your dashboard like the one below.

<img src="../../docs/images/wandb_screenshot.png" alt="wandb screenshot" width="500" />