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t5-experiments

This repo is based on 🤗 Transfomers implementation of the T5 model and BERT. T5 data processing pipeline is used from the original T5 repository for pre-training (span corruption, prefix-lm) and fine-tuning. BERT data processing pipeline is used from Megatron-LM.

Multi-gpu and multi-node training with Horovod is supported. APEX is used for FP16 and mixed-precision training. Sparse Attention from DeepSpeed is used.

BERT model supports such additional features as pre-attention layer norm, sparse attention, relative position and rotary embeddings.

T5 and BERT pre-training is implemented in run_(model_type)_pretraining.py scripts.

Install requirements

Install requirements after cloning the repo:

grep -v "^#" requirements.txt | xargs -n 1 -L 1 pip install

Currenty, T5 text-to-text installation might install tf2.8.0+, downgrade TF related packages with:

pip install tensorflow==2.6.0 tensorflow-estimator==2.6.0 tensorflow-text==2.6.0 tensorflow-io-gcs-filesystem==0.21.0 keras==2.6.0

todo: reorder reqs in requirements.txt.

Install Horovod

Depending on your setup just pip install horovod==0.24.2 might work.

Building Horovod with NCCL for PyTorch:

HOROVOD_NCCL_HOME=... HOROVOD_GPU_OPERATIONS=NCCL HOROVOD_WITH_PYTORCH=1 pip install --no-cache-dir horovod[pytorch]==0.24.2 --no-binary=horovod

check installation with

horovodrun --check-build

For further details check Horovod documentation: https://horovod.readthedocs.io/en/stable/install_include.html

Install APEX

Install APEX https://github.com/NVIDIA/apex#quick-start

git clone https://github.com/NVIDIA/apex
cd apex
pip install -v --disable-pip-version-check --no-cache-dir --global-option="--cpp_ext" --global-option="--cuda_ext" ./

apex.amp is moved to torch.cuda.amp https://github.com/NVIDIA/apex/issues/818, but:

speed: APEX O1 < torch.cuda.amp < APEX O2

resources (unordered):

• https://pytorch.org/tutorials/recipes/recipes/amp_recipe.html
• https://pytorch.org/docs/stable/notes/amp_examples.html
• https://spell.ml/blog/mixed-precision-training-with-pytorch-Xuk7YBEAACAASJam
• https://pytorch.org/blog/accelerating-training-on-nvidia-gpus-with-pytorch-automatic-mixed-precision/
• https://github.com/horovod/horovod/issues/1089
• https://github.com/NVIDIA/apex/issues/818

Install DeepSpeed

DeepSpeed Sparse attention supports only GPUs with compute compatibility >= 7 (V100, T4, A100), CUDA 10.1, 10.2, 11.0, or 11.1 and runs only in FP16 mode (as of DeepSpeed 0.6.0).

pip install triton==1.0.0
DS_BUILD_SPARSE_ATTN=1 pip install deepspeed==0.6.0 --global-option="build_ext" --global-option="-j8" --no-cache

and check installation with

ds_report

Triron 1.1.1

Triton 1.1.1 brings x2 speed-up to sparse operations on A100, but DeepSpeed (0.6.5) currenly supports only triton 1.0.0. DeepSpeed fork with triton 1.1.1 support could be used in the cases where such speed-up is needed:

pip install triton==1.1.1
git clone https://github.com/yurakuratov/DeepSpeed.git
cd DeepSpeed
DS_BUILD_SPARSE_ATTN=1 pip install -e . --global-option="build_ext" --global-option="-j8" --no-cache

and run sparse ops tests with

cd tests/unit
pytest -v test_sparse_attention.py

T5 Pre-training

T5-small baseline

export CUDA_VISIBLE_DEVICES=4,5; horovodrun --gloo -np 2 python run_t5_pretraining.py \
        --batch_size 32 \
        --gradient_accumulation_steps 2 \
        --save_interval 100000 \
        --log_interval 500 \
        --iters 1100000 \
        --data_path ~/data/ThePile/Wikipedia/preprocessed_shards \
        --model_path ./runs/small_wiki_bs_128 \
        --input_seq_len 512 \
        --target_seq_len 192 \
        --lr 5e-05 \
        --weight_decay 1e-05 \
        --model_cfg ./t5configs/t5-small.json \
        --model_cls modeling_t5:T5ForConditionalGeneration

T5-base with custom layers:

and continue interrupted training

export CUDA_VISIBLE_DEVICES=0,1,2,3; horovodrun --gloo -np 4 python run_t5_pretraining.py \
        --batch_size 8 \
        --gradient_accumulation_steps 4 \
        --save_interval 75000 \
        --log_interval 500 \
        --iters 1000000 --data_path ~/data/ThePile/Wikipedia/preprocessed_shards \
        --model_path ./runs/base_wiki_enc_only_cdq_fixed_pos_wo_tanh \
        --input_seq_len 512 \
        --target_seq_len 192 \
        --lr 5e-05 \
        --weight_decay 1e-05 \
        --model_cls modeling_t5:T5ForConditionalGeneration \
        --model_cfg t5configs/t5-base-only-cdQ.json \
        --init_checkpoint ./runs/base_wiki_enc_only_cdq_fixed_pos_wo_tanh/model_150000.pth

T5 Fine-tuning with DeepPavlov

python -m deeppavlov train config_name

Gradient accumulation for dp:T5Text2TextModel, e.g.:

• batch_size: 32
• sub_batch_size: 16

means that full batch of size batch_size will be splited on two sub-batches of size sub_batch_size to accumulate their gradients.

Fine-tuning on GLUE

Base configuration files are at ./dp_configs/glue

Fine-tuning and evaluation could be done with command:

export CUDA_VISIBLE_DEVICES=6; python evaluate_model.py single \
        --pretrained-checkpoint ./runs/small_wiki_bs_128/model_1100000.pth \
        --task-config ./dp_configs/glue \
        --suffix bs_32/run_0 \
        --train-batch-size 32

pretrained-checkpoint is a path to pretrained checkpoint that would be trained and evaluated, task-config is a folder with DP configs (or single DP config), suffix would be appended to a model path. Check evaluate_model.py for more details.

GLUE mixture from T5

config: ./dp_configs/glue/glue_mixture.json

Use save_every_n_batches parameter to save the model, set metrics: [] and evaluation_targets: [] in DP configs.

Train model on datasets mixture, check all available options in evaluate_model.py:train_mixture():

export CUDA_VISIBLE_DEVICES=1; python evaluate_model.py train-mixture \
        --pretrained-checkpoint ./runs/small_wiki_bs_128/model_1100000.pth \
        --task-config ./dp_configs/glue/glue_mixture.json  \
        --suffix bs_128 \
        --train-batch-size 128

Evaluation for all checkpoints in checkpoint folder, saves best checkpoints and evaluation results:

export CUDA_VISIBLE_DEVICES=0; python evaluate_model.py mixture \
        --checkpoint ./runs/small_wiki_bs_128/glue/mixture/bs_128/ \
        --pretrained-checkpoint ./runs/small_wiki_bs_128/model_1100000.pth \
        --task-config ./dp_configs/glue \
        --save-best

Collecting results

To get the best scores for all fine-tuned models and tasks run:

python evaluate_model.py collect-metrics \
        --pretrained-checkpoint ./runs/small_wiki_bs_128/model_1100000.pth --clean > report.txt

use --clean option to delete all models checkpoints except the best ones for each task.

Prepare submission for GLUE Leaderboard:

TBD

QQP

QQP is currently not available via tfds: https://github.com/tensorflow/datasets/pull/3031

to hot-fix this go to the source code of installed tfds tensorflow_datasets/text/glue.py:215 and replace QQP data url with https://dl.fbaipublicfiles.com/glue/data/QQP.zip

Fine-tuning on WMT

WMT configs could be found in ./dp_configs/wmt

Training with Horovod+DeepPavlov:

export CUDA_VISIBLE_DEVICES=0,1,2,3,4,5,6,7; horovodrun --gloo -np 8 python -m deeppavlov train ./dp_configs/ende_hvd.json

Multi-gpu training and evaluating with evaluate_model.py (recommended):

export CUDA_VISIBLE_DEVICES=0,1,2,3,4,5,6,7; python evaluate_model.py single \
        --pretrained-checkpoint ./runs/small_wiki_bs_128/model_1100000.pth \
        --task-config ./dp_configs/wmt/ende.json \
        --suffix bs_128_hvd/run_0 \
        --train-batch-size 16 \
        --lr 5e-05

BERT pretraining

Data preprocessing readme

FP16 for pretraining

add --fp16 and --apex_opt_lvl O2 or --apex_opt_lvl O1 (default) as arguments to run_t5_pretraining.py

Adafactor optimizer

Adafactor was used to train such models as T5, BigBird, PaLM and others. Adafactor lowers required memory by keeping moving average of per-parameter second moments factorized.

Adafactor parameters:

• scale_parameter - lr is scaled by root mean square of parameter: lr * RMS(p)
• relative_step - lr = 1/sqrt(step)
• warmup_init - linear warm up from 1e-06 to 0.01 at 10k steps, works only in combination with relative_step

Adafactor can be used with constant lr / lr schedulers. In this case, relative_step and warmup_init should be set to False. scale_parameter is does not depend on learning rate schedules and can be used with external learning rates.

example for pretraining scripts:

--optimizer Adafactor --lr 1e-03 --scale_parameter \
--lr_scheduler constant_with_warmup --num_warmup_steps 10000

e.g. for DP config

"optimizer": "Adafactor",
"optimizer_parameters": {
        "lr": 1e-03,
        "weight_decay": 0.0,
        "scale_parameter": true,
        "relative_step": false,
        "warmup_init": false
}

Sparse Attention

BERT model training supports sparse attentions from DeepSpeed.

DeepSpeed Sparse attention docpage -- https://www.deepspeed.ai/tutorials/sparse-attention.

Configure Sparse Attention

SparseAttention parameters are passed to the model with HF model configuration file:

"sparse_config_cls": "deepspeed.ops.sparse_attention:BigBirdSparsityConfig",
"sparse_attention": {
  "num_heads": 12,
  "block": 16,
  "different_layout_per_head": true,
  "num_sliding_window_blocks": 1,
  "num_global_blocks": 1,
  "num_random_blocks": 1
}

You can also check bert_base_uncased-4L_sparse.json config example in bert_configs folder.