Merge branch 'huggingface/master'

examples/README.md

@@ -5,11 +5,35 @@ similar API between the different models.
 
 | Section                    | Description                                                                                                                                                |
 |----------------------------|------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| [TensorFlow 2.0 models on GLUE](#TensorFlow-2.0-Bert-models-on-GLUE) | Examples running BERT TensorFlow 2.0 model on the GLUE tasks. 
 | [Language Model fine-tuning](#language-model-fine-tuning) | Fine-tuning the library models for language modeling on a text dataset. Causal language modeling for GPT/GPT-2, masked language modeling for BERT/RoBERTa. |
 | [Language Generation](#language-generation) | Conditional text generation using the auto-regressive models of the library: GPT, GPT-2, Transformer-XL and XLNet.                                         |
 | [GLUE](#glue) | Examples running BERT/XLM/XLNet/RoBERTa on the 9 GLUE tasks. Examples feature distributed training as well as half-precision.                              |
-| [SQuAD](#squad) | Using BERT for question answering, examples with distributed training.                                                                                  |
-| [Multiple Choice](#multiple choice) | Examples running BERT/XLNet/RoBERTa on the SWAG/RACE/ARC tasks. 
+| [SQuAD](#squad) | Using BERT/XLM/XLNet/RoBERTa for question answering, examples with distributed training.                                                                                  |
+| [Multiple Choice](#multiple-choice) | Examples running BERT/XLNet/RoBERTa on the SWAG/RACE/ARC tasks. 
+| [Named Entity Recognition](#named-entity-recognition) | Using BERT for Named Entity Recognition (NER) on the CoNLL 2003 dataset, examples with distributed training.                                                                                  |
+
+## TensorFlow 2.0 Bert models on GLUE
+
+Based on the script [`run_tf_glue.py`](https://github.com/huggingface/transformers/blob/master/examples/run_tf_glue.py).
+
+Fine-tuning the library TensorFlow 2.0 Bert model for sequence classification on the  MRPC task of the GLUE benchmark: [General Language Understanding Evaluation](https://gluebenchmark.com/).
+
+This script has an option for mixed precision (Automatic Mixed Precision / AMP) to run models on Tensor Cores (NVIDIA Volta/Turing GPUs) and future hardware and an option for XLA, which uses the XLA compiler to reduce model runtime.
+Options are toggled using `USE_XLA` or `USE_AMP` variables in the script.
+These options and the below benchmark are provided by @tlkh.
+
+Quick benchmarks from the script (no other modifications):
+
+| GPU    | Mode | Time (2nd epoch) | Val Acc (3 runs) |
+| --------- | -------- | ----------------------- | ----------------------|
+| Titan V | FP32 | 41s | 0.8438/0.8281/0.8333 |
+| Titan V | AMP | 26s | 0.8281/0.8568/0.8411 |
+| V100    | FP32 | 35s | 0.8646/0.8359/0.8464 |
+| V100    | AMP | 22s | 0.8646/0.8385/0.8411 |
+| 1080 Ti | FP32 | 55s | - | 
+
+Mixed precision (AMP) reduces the training time considerably for the same hardware and hyper-parameters (same batch size was used).
 
 ## Language model fine-tuning
 
@@ -283,17 +307,17 @@ The results  are the following:
   loss = 0.04755385363816904
 ```
 
-##Multiple Choice
+## Multiple Choice
 
 Based on the script [`run_multiple_choice.py`]().
 
 #### Fine-tuning on SWAG
 Download [swag](https://github.com/rowanz/swagaf/tree/master/data) data
 
-```
+```bash
 #training on 4 tesla V100(16GB) GPUS
 export SWAG_DIR=/path/to/swag_data_dir
-python ./examples/single_model_scripts/run_multiple_choice.py \
+python ./examples/run_multiple_choice.py \
 --model_type roberta \
 --task_name swag \
 --model_name_or_path roberta-base \
@@ -390,3 +414,103 @@ exact_match = 86.91
 This fine-tuneds model is available as a checkpoint under the reference
 `bert-large-uncased-whole-word-masking-finetuned-squad`.
 
+## Named Entity Recognition
+
+Based on the script [`run_ner.py`](https://github.com/huggingface/transformers/blob/master/examples/run_ner.py).
+This example fine-tune Bert Multilingual on GermEval 2014 (German NER).
+Details and results for the fine-tuning provided by @stefan-it.
+
+### Data (Download and pre-processing steps)
+
+Data can be obtained from the [GermEval 2014](https://sites.google.com/site/germeval2014ner/data) shared task page.
+
+Here are the commands for downloading and pre-processing train, dev and test datasets. The original data format has four (tab-separated) columns, in a pre-processing step only the two relevant columns (token and outer span NER annotation) are extracted:
+
+```bash
+curl -L 'https://sites.google.com/site/germeval2014ner/data/NER-de-train.tsv?attredirects=0&d=1' \
+| grep -v "^#" | cut -f 2,3 | tr '\t' ' ' > train.txt.tmp
+curl -L 'https://sites.google.com/site/germeval2014ner/data/NER-de-dev.tsv?attredirects=0&d=1' \
+| grep -v "^#" | cut -f 2,3 | tr '\t' ' ' > dev.txt.tmp
+curl -L 'https://sites.google.com/site/germeval2014ner/data/NER-de-test.tsv?attredirects=0&d=1' \
+| grep -v "^#" | cut -f 2,3 | tr '\t' ' ' > test.txt.tmp
+```
+
+The GermEval 2014 dataset contains some strange "control character" tokens like `'\x96', '\u200e', '\x95', '\xad' or '\x80'`. One problem with these tokens is, that `BertTokenizer` returns an empty token for them, resulting in misaligned `InputExample`s. I wrote a script that a) filters these tokens and b) splits longer sentences into smaller ones (once the max. subtoken length is reached).
+
+```bash
+wget "https://raw.githubusercontent.com/stefan-it/fine-tuned-berts-seq/master/scripts/preprocess.py"
+```
+Let's define some variables that we need for further pre-processing steps and training the model:
+
+```bash
+export MAX_LENGTH=128
+export BERT_MODEL=bert-base-multilingual-cased
+```
+
+Run the pre-processing script on training, dev and test datasets:
+
+```bash
+python3 preprocess.py train.txt.tmp $BERT_MODEL $MAX_LENGTH > train.txt
+python3 preprocess.py dev.txt.tmp $BERT_MODEL $MAX_LENGTH > dev.txt
+python3 preprocess.py test.txt.tmp $BERT_MODEL $MAX_LENGTH > test.txt
+```
+
+The GermEval 2014 dataset has much more labels than CoNLL-2002/2003 datasets, so an own set of labels must be used:
+
+```bash
+cat train.txt dev.txt test.txt | cut -d " " -f 2 | grep -v "^$"| sort | uniq > labels.txt
+```
+
+### Training
+
+Additional environment variables must be set:
+
+```bash
+export OUTPUT_DIR=germeval-model
+export BATCH_SIZE=32
+export NUM_EPOCHS=3
+export SAVE_STEPS=750
+export SEED=1
+```
+
+To start training, just run:
+
+```bash
+python3 run_ner.py --data_dir ./ \
+--model_type bert \
+--labels ./labels.txt \
+--model_name_or_path $BERT_MODEL \
+--output_dir $OUTPUT_DIR \
+--max_seq_length  $MAX_LENGTH \
+--num_train_epochs $NUM_EPOCHS \
+--per_gpu_train_batch_size $BATCH_SIZE \
+--save_steps $SAVE_STEPS \
+--seed $SEED \
+--do_train \
+--do_eval \
+--do_predict
+```
+
+If your GPU supports half-precision training, just add the `--fp16` flag. After training, the model will be both evaluated on development and test datasets.
+
+### Evaluation
+
+Evaluation on development dataset outputs the following for our example:
+
+```bash
+10/04/2019 00:42:06 - INFO - __main__ -   ***** Eval results  *****
+10/04/2019 00:42:06 - INFO - __main__ -     f1 = 0.8623348017621146
+10/04/2019 00:42:06 - INFO - __main__ -     loss = 0.07183869666975543
+10/04/2019 00:42:06 - INFO - __main__ -     precision = 0.8467916366258111
+10/04/2019 00:42:06 - INFO - __main__ -     recall = 0.8784592370979806
+```
+
+On the test dataset the following results could be achieved:
+
+```bash
+10/04/2019 00:42:42 - INFO - __main__ -   ***** Eval results  *****
+10/04/2019 00:42:42 - INFO - __main__ -     f1 = 0.8614389652384803
+10/04/2019 00:42:42 - INFO - __main__ -     loss = 0.07064602487454782
+10/04/2019 00:42:42 - INFO - __main__ -     precision = 0.8604651162790697
+10/04/2019 00:42:42 - INFO - __main__ -     recall = 0.8624150210424085
+```

examples/contrib/run_swag.py

@@ -31,9 +31,13 @@ import torch
 from torch.utils.data import (DataLoader, RandomSampler, SequentialSampler,
                               TensorDataset)
 from torch.utils.data.distributed import DistributedSampler
-from tqdm import tqdm, trange
 
-from tensorboardX import SummaryWriter
+try:
+    from torch.utils.tensorboard import SummaryWriter
+except:
+    from tensorboardX import SummaryWriter
+
+from tqdm import tqdm, trange
 
 from transformers import (WEIGHTS_NAME, BertConfig,
                                   BertForMultipleChoice, BertTokenizer)

examples/distillation/README.md

-# DistilBERT
+# Distil*
 
-This folder contains the original code used to train DistilBERT as well as examples showcasing how to use DistilBERT.
+This folder contains the original code used to train Distil* as well as examples showcasing how to use DistilBERT and DistilGPT2.
+
+**2019, October 3rd - Update** We release our [NeurIPS workshop paper](https://arxiv.org/abs/1910.01108) explaining our approach on **DistilBERT**. It includes updated results and further experiments. We applied the same method to GPT2 and release the weights of **DistilGPT2**. DistilGPT2 is two times faster and 33% smaller than GPT2. **The paper superseeds our [previous blogpost](https://medium.com/huggingface/distilbert-8cf3380435b5) with a different distillation loss and better performances. Please use the paper as a reference when comparing/reporting results on DistilBERT.**
 
 **2019, September 19th - Update:** We fixed bugs in the code and released an upadted version of the weights trained with a modification of the distillation loss. DistilBERT now reaches 97% of `BERT-base`'s performance on GLUE, and 86.9 F1 score on SQuAD v1.1 dev set (compared to 88.5 for `BERT-base`). We will publish a formal write-up of our approach in the near future!
 
-## What is DistilBERT
+## What is Distil*
+
+Distil* is a class of compressed models that started with DistilBERT. DistilBERT stands for Distillated-BERT. DistilBERT is a small, fast, cheap and light Transformer model based on Bert architecture. It has 40% less parameters than `bert-base-uncased`, runs 60% faster while preserving 97% of BERT's performances as measured on the GLUE language understanding benchmark. DistilBERT is trained using knowledge distillation, a technique to compress a large model called the teacher into a smaller model called the student. By distillating Bert, we obtain a smaller Transformer model that bears a lot of similarities with the original BERT model while being lighter, smaller and faster to run. DistilBERT is thus an interesting option to put large-scaled trained Transformer model into production.
 
-DistilBERT stands for Distillated-BERT. DistilBERT is a small, fast, cheap and light Transformer model based on Bert architecture. It has 40% less parameters than `bert-base-uncased`, runs 60% faster while preserving 97% of BERT's performances as measured on the GLUE language understanding benchmark. DistilBERT is trained using knowledge distillation, a technique to compress a large model called the teacher into a smaller model called the student. By distillating Bert, we obtain a smaller Transformer model that bears a lot of similarities with the original BERT model while being lighter, smaller and faster to run. DistilBERT is thus an interesting option to put large-scaled trained Transformer model into production.
+We have applied the same method to GPT2 and release the weights of the compressed model. On the [WikiText-103](https://blog.einstein.ai/the-wikitext-long-term-dependency-language-modeling-dataset/) benchmark, GPT2 reaches a perplexity on the test set of 15.0 compared to 18.5 for DistilGPT2 (after fine-tuning on the train set).
 
-For more information on DistilBERT, please refer to our [detailed blog post](https://medium.com/huggingface/smaller-faster-cheaper-lighter-introducing-distilbert-a-distilled-version-of-bert-8cf3380435b5
-). *Please note that we will publish a formal write-up with updated and more complete results in the near future (September 19th).*
+For more information on DistilBERT, please refer to our [NeurIPS workshop paper](https://arxiv.org/abs/1910.01108).
 
-Here's the updated results on the dev sets of GLUE:
+Here are the results on the dev sets of GLUE:
 
-| Model      | Macro-score | CoLA | MNLI | MRPC | QNLI | QQP | RTE | SST-2 | STS-B | WNLI |
+| Model      | Macro-score | CoLA | MNLI | MRPC | QNLI | QQP  | RTE  | SST-2| STS-B| WNLI |
 | :---:      |    :---:    | :---:| :---:| :---:| :---:| :---:| :---:| :---:| :---:| :---:|
 | BERT-base  |  **77.6**   | 48.9 | 84.3 | 88.6 | 89.3 | 89.5 | 71.3 | 91.7 | 91.2 | 43.7 |
-| DistilBERT |  **75.2**   | 49.1 | 81.8 | 90.2 | 87.0 | 89.2 | 62.9 | 92.7 | 90.7 | 44.4 |
+| DistilBERT |  **76.8**   | 49.1 | 81.8 | 90.2 | 90.2 | 89.2 | 62.9 | 92.7 | 90.7 | 44.4 |
 
 ## Setup
 
 This part of the library has only be tested with Python3.6+. There are few specific dependencies to install before launching a distillation, you can install them with the command `pip install -r requirements.txt`. 
 
-**Important note:** The training scripts have been updated to support PyTorch v1.2.0 (there are breakings changes compared to v1.1.0). It is important to note that there is a small internal bug in the current version of PyTorch available on pip that causes a memory leak in our training/distillation. It has been recently fixed and will likely be integrated into the next release. For the moment, we recommend to [compile PyTorch from source](https://github.com/pytorch/pytorch#from-source). Please refer to [issue 1179](https://github.com/huggingface/transformers/issues/1179) for more details.
+**Important note:** The training scripts have been updated to support PyTorch v1.2.0 (there are breakings changes compared to v1.1.0).
 
 ## How to use DistilBERT
 
-Transformers includes two pre-trained DistilBERT models, currently only provided for English (we are investigating the possibility to train and release a multilingual version of DistilBERT):
+Transformers includes two pre-trained Distil* models, currently only provided for English (we are investigating the possibility to train and release a multilingual version of DistilBERT):
 
 - `distilbert-base-uncased`: DistilBERT English language model pretrained on the same data used to pretrain Bert (concatenation of the Toronto Book Corpus and full English Wikipedia) using distillation with the supervision of the `bert-base-uncased` version of Bert. The model has 6 layers, 768 dimension and 12 heads, totalizing 66M parameters.
 - `distilbert-base-uncased-distilled-squad`: A finetuned version of `distilbert-base-uncased` finetuned using (a second step of) knwoledge distillation on SQuAD 1.0. This model reaches a F1 score of 86.9 on the dev set (for comparison, Bert `bert-base-uncased` version reaches a 88.5 F1 score).
+- `distilgpt2`: DistilGPT2 English language model pretrained with the supervision of `gpt2` (the smallest version of GPT2) on [OpenWebTextCorpus](https://skylion007.github.io/OpenWebTextCorpus/), a reproduction of OpenAI's WebText dataset and . The model has 6 layers, 768 dimension and 12 heads, totalizing 82M (compared to 124M parameters for GPT2). On average, DistilGPT2 is two times faster than GPT2.
+- and more to come! 🤗🤗🤗
 
 Using DistilBERT is very similar to using BERT. DistilBERT share the same tokenizer as BERT's `bert-base-uncased` even though we provide a link to this tokenizer under the `DistilBertTokenizer` name to have a consistent naming between the library models.
 
@@ -42,9 +47,11 @@ outputs = model(input_ids)
 last_hidden_states = outputs[0]  # The last hidden-state is the first element of the output tuple
 ```
 
-## How to train DistilBERT
+Similarly, using DistilGPT2 simply consists in calling the GPT2 classes from a different pretrained checkpoint: `model = GPT2Model.from_pretrained('distilgpt2')`.
+
+## How to train Distil*
 
-In the following, we will explain how you can train your own compressed model.
+In the following, we will explain how you can train DistilBERT.
 
 ### A. Preparing the data
 
@@ -57,7 +64,8 @@ First, we will binarize the data, i.e. tokenize the data and convert each token
 ```bash
 python scripts/binarized_data.py \
     --file_path data/dump.txt \
-    --bert_tokenizer bert-base-uncased \
+    --tokenizer_type bert \
+    --tokenizer_name bert-base-uncased \
     --dump_file data/binarized_text
 ```
 
@@ -66,7 +74,8 @@ Our implementation of masked language modeling loss follows [XLM](https://github
 ```bash
 python scripts/token_counts.py \
     --data_file data/binarized_text.bert-base-uncased.pickle \
-    --token_counts_dump data/token_counts.bert-base-uncased.pickle
+    --token_counts_dump data/token_counts.bert-base-uncased.pickle \
+    --vocab_size 30522
 ```
 
 ### B. Training
@@ -75,6 +84,12 @@ Training with distillation is really simple once you have pre-processed the data
 
 ```bash
 python train.py \
+    --student_type distilbert \
+    --student_config training_configs/distilbert-base-uncased.json \
+    --teacher_type bert \
+    --teacher_name bert-base-uncased \
+    --alpha_ce 5.0 --alpha_mlm 2.0 --alpha_cos 1.0 --mlm \
+    --freeze_pos_embs \
     --dump_path serialization_dir/my_first_training \
     --data_file data/binarized_text.bert-base-uncased.pickle \
     --token_counts data/token_counts.bert-base-uncased.pickle \
@@ -83,7 +98,7 @@ python train.py \
 
 By default, this will launch a training on a single GPU (even if more are available on the cluster). Other parameters are available in the command line, please look in `train.py` or run `python train.py --help` to list them.
 
-We highly encourage you to use distributed training for training DistilBert as the training corpus is quite large. Here's an example that runs a distributed training on a single node having 4 GPUs:
+We highly encourage you to use distributed training for training DistilBERT as the training corpus is quite large. Here's an example that runs a distributed training on a single node having 4 GPUs:
 
 ```bash
 export NODE_RANK=0
@@ -105,11 +120,30 @@ python -m torch.distributed.launch \
     train.py \
         --force \
         --n_gpu $WORLD_SIZE \
+        --student_type distilbert \
+        --student_config training_configs/distilbert-base-uncased.json \
+        --teacher_type bert \
+        --teacher_name bert-base-uncased \
+        --alpha_ce 0.33 --alpha_mlm 0.33 --alpha_cos 0.33 --mlm \
+        --freeze_pos_embs \
+        --dump_path serialization_dir/my_first_training \
         --data_file data/binarized_text.bert-base-uncased.pickle \
-        --token_counts data/token_counts.bert-base-uncased.pickle \
-        --dump_path serialization_dir/my_first_distillation
+        --token_counts data/token_counts.bert-base-uncased.pickle
 ```
 
-**Tips:** Starting distillated training with good initialization of the model weights is crucial to reach decent performance. In our experiments, we initialized our model from a few layers of the teacher (Bert) itself! Please refer to `scripts/extract_for_distil.py` to create a valid initialization checkpoint and use `--from_pretrained_weights` and `--from_pretrained_config` arguments to use this initialization for the distilled training!
+**Tips:** Starting distillated training with good initialization of the model weights is crucial to reach decent performance. In our experiments, we initialized our model from a few layers of the teacher (Bert) itself! Please refer to `scripts/extract.py` and `scripts/extract_distilbert.py` to create a valid initialization checkpoint and use `--student_pretrained_weights` argument to use this initialization for the distilled training!
 
 Happy distillation!
+
+## Citation
+
+If you find the ressource useful, you should cite the following paper:
+
+```
+@inproceedings{sanh2019distilbert,
+  title={DistilBERT, a distilled version of BERT: smaller, faster, cheaper and lighter},
+  author={Sanh, Victor and Debut, Lysandre and Chaumond, Julien and Wolf, Thomas},
+  booktitle={NeurIPS EMC^2 Workshop},
+  year={2019}
+}
+```
\ No newline at end of file

examples/distillation/distiller.py

@@ -12,14 +12,13 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-""" The distiller to distil DistilBERT
-    adapted in part from Facebook, Inc XLM model (https://github.com/facebookresearch/XLM)
+""" The distiller to distil the student.
+    Adapted in part from Facebook, Inc XLM model (https://github.com/facebookresearch/XLM)
 """
 import os
 import math
 import psutil
 import time
-from tensorboardX import SummaryWriter
 from tqdm import trange, tqdm
 import numpy as np
 import psutil
@@ -28,16 +27,24 @@ import torch
 import torch.nn as nn
 import torch.nn.functional as F
 from torch.optim import AdamW
+from torch.utils.data.distributed import DistributedSampler
+from torch.utils.data import RandomSampler, BatchSampler, DataLoader
+
+try:
+    from torch.utils.tensorboard import SummaryWriter
+except:
+    from tensorboardX import SummaryWriter
 
 from transformers import WarmupLinearSchedule
 
 from utils import logger
-from dataset import Dataset
+from lm_seqs_dataset import LmSeqsDataset
+from grouped_batch_sampler import GroupedBatchSampler, create_lengths_groups
 
 class Distiller:
     def __init__(self,
                  params: dict,
-                 dataloader: Dataset,
+                 dataset: LmSeqsDataset,
                  token_probs: torch.tensor,
                  student: nn.Module,
                  teacher: nn.Module):
@@ -50,24 +57,36 @@ class Distiller:
         self.student = student
         self.teacher = teacher
 
-        self.dataloader = dataloader
-        if self.params.n_gpu > 1:
-            self.dataloader.split()
-        self.get_iterator(seed=params.seed)
+        self.student_config = student.config
+        self.vocab_size = student.config.vocab_size
+
+        if params.n_gpu <= 1:
+            sampler = RandomSampler(dataset)
+        else:
+            sampler = DistributedSampler(dataset)
+
+        if params.group_by_size:
+            groups = create_lengths_groups(lengths=dataset.lengths, k=params.max_model_input_size)
+            sampler = GroupedBatchSampler(sampler=sampler, group_ids=groups, batch_size=params.batch_size)
+        else:
+            sampler = BatchSampler(sampler=sampler, batch_size=params.batch_size, drop_last=False)
+
+        self.dataloader = DataLoader(dataset=dataset,
+                                     batch_sampler=sampler,
+                                     collate_fn=dataset.batch_sequences)
 
         self.temperature = params.temperature
         assert self.temperature > 0.
 
         self.alpha_ce = params.alpha_ce
         self.alpha_mlm = params.alpha_mlm
+        self.alpha_clm = params.alpha_clm
         self.alpha_mse = params.alpha_mse
         self.alpha_cos = params.alpha_cos
-        assert self.alpha_ce >= 0.
-        assert self.alpha_mlm >= 0.
-        assert self.alpha_mse >= 0.
-        assert self.alpha_cos >= 0.
-        assert self.alpha_ce + self.alpha_mlm + self.alpha_mse + self.alpha_cos > 0.
 
+        self.mlm = params.mlm
+        if self.mlm:
+            logger.info(f'Using MLM loss for LM step.')
             self.mlm_mask_prop = params.mlm_mask_prop
             assert 0.0 <= self.mlm_mask_prop <= 1.0
             assert params.word_mask + params.word_keep + params.word_rand == 1.0
@@ -77,6 +96,8 @@ class Distiller:
             if self.fp16:
                 self.pred_probs = self.pred_probs.half()
                 self.token_probs = self.token_probs.half()
+        else:
+            logger.info(f'Using CLM loss for LM step.')
 
         self.epoch = 0
         self.n_iter = 0
@@ -86,12 +107,13 @@ class Distiller:
         self.last_loss = 0
         self.last_loss_ce = 0
         self.last_loss_mlm = 0
+        self.last_loss_clm = 0
         if self.alpha_mse > 0.: self.last_loss_mse = 0
         if self.alpha_cos > 0.: self.last_loss_cos = 0
         self.last_log = 0
 
         self.ce_loss_fct = nn.KLDivLoss(reduction='batchmean')
-        self.mlm_loss_fct = nn.CrossEntropyLoss(ignore_index=-1)
+        self.lm_loss_fct = nn.CrossEntropyLoss(ignore_index=-1)
         if self.alpha_mse > 0.:
             self.mse_loss_fct = nn.MSELoss(reduction='sum')
         if self.alpha_cos > 0.:
@@ -99,7 +121,7 @@ class Distiller:
 
         logger.info('--- Initializing model optimizer')
         assert params.gradient_accumulation_steps >= 1
-        self.num_steps_epoch = int(len(self.dataloader) / params.batch_size) + 1
+        self.num_steps_epoch = len(self.dataloader)
         num_train_optimization_steps = int(self.num_steps_epoch / params.gradient_accumulation_steps * params.n_epoch) + 1
 
         no_decay = ['bias', 'LayerNorm.weight']
@@ -140,42 +162,17 @@ class Distiller:
                 logger.info("Using nn.parallel.DistributedDataParallel for distributed training.")
                 self.student = DistributedDataParallel(self.student,
                                                        device_ids=[params.local_rank],
-                                                       output_device=params.local_rank)
+                                                       output_device=params.local_rank,
+                                                       find_unused_parameters=True)
 
         self.is_master = params.is_master
         if self.is_master:
             logger.info('--- Initializing Tensorboard')
             self.tensorboard = SummaryWriter(log_dir=os.path.join(self.dump_path, 'log', 'train'))
-            self.tensorboard.add_text(tag='config', text_string=str(self.params), global_step=0)
-
-    def get_iterator(self,
-                     seed: int = None):
-        """
-        Initialize the data iterator.
-        Each process has its own data iterator (iterating on his own random portion of the dataset).
+            self.tensorboard.add_text(tag='config/training', text_string=str(self.params), global_step=0)
+            self.tensorboard.add_text(tag='config/student', text_string=str(self.student_config), global_step=0)
 
-        Input:
-        ------
-            seed: `int` - The random seed.
-        """
-        logger.info('--- Initializing Data Iterator')
-        self.data_iterator = self.dataloader.get_iterator(seed=seed)
-
-    def get_batch(self):
-        """
-        Call the data iterator to output a new batch.
-        If the data iterator went through the whole dataset, create a new iterator.
-        """
-        assert hasattr(self, 'data_iterator')
-        try:
-            x = next(self.data_iterator)
-        except StopIteration:
-            logger.warning('--- Went through the whole dataset. Creating new data iterator.')
-            self.data_iterator = self.dataloader.get_iterator()
-            x = next(self.data_iterator)
-        return x
-
-    def prepare_batch(self,
+    def prepare_batch_mlm(self,
                           batch):
         """
         Prepare the batch: from the token_ids and the lenghts, compute the attention mask and the masked label for MLM.
@@ -222,7 +219,7 @@ class Distiller:
                 assert pred_mask.sum().item() % 8 == 0, pred_mask.sum().item()
 
         _token_ids_real = token_ids[pred_mask]
-        _token_ids_rand = _token_ids_real.clone().random_(self.params.vocab_size)
+        _token_ids_rand = _token_ids_real.clone().random_(self.vocab_size)
         _token_ids_mask = _token_ids_real.clone().fill_(self.params.special_tok_ids['mask_token'])
         probs = torch.multinomial(self.pred_probs, len(_token_ids_real), replacement=True)
         _token_ids = _token_ids_mask * (probs == 0).long() + _token_ids_real * (probs == 1).long() + _token_ids_rand * (probs == 2).long()
@@ -230,8 +227,41 @@ class Distiller:
 
         mlm_labels[~pred_mask] = -1 # previously `mlm_labels[1-pred_mask] = -1`, cf pytorch 1.2.0 compatibility
 
+        # sanity checks
+        assert 0 <= token_ids.min() <= token_ids.max() < self.vocab_size
+
         return token_ids, attn_mask, mlm_labels
 
+    def prepare_batch_clm(self,
+                          batch):
+        """
+        Prepare the batch: from the token_ids and the lenghts, compute the attention mask and the labels for CLM.
+
+        Input:
+        ------
+            batch: `Tuple`
+                token_ids: `torch.tensor(bs, seq_length)` - The token ids for each of the sequence. It is padded.
+                lengths: `torch.tensor(bs)` - The lengths of each of the sequences in the batch.
+
+        Output:
+        -------
+            token_ids: `torch.tensor(bs, seq_length)` - The token ids after the modifications for MLM.
+            attn_mask: `torch.tensor(bs, seq_length)` - The attention mask for the self-attention.
+            clm_labels: `torch.tensor(bs, seq_length)` - The causal languge modeling labels. There is a -1 where there is nothing to predict.
+        """
+        token_ids, lengths = batch
+        token_ids, lengths = self.round_batch(x=token_ids, lengths=lengths)
+        assert token_ids.size(0) == lengths.size(0)
+
+        attn_mask = (torch.arange(token_ids.size(1), dtype=torch.long, device=lengths.device) < lengths[:, None])
+        clm_labels = token_ids.new(token_ids.size()).copy_(token_ids)
+        clm_labels[~attn_mask] = -1 # previously `clm_labels[1-attn_mask] = -1`, cf pytorch 1.2.0 compatibility
+
+        # sanity checks
+        assert 0 <= token_ids.min() <= token_ids.max() < self.vocab_size
+
+        return token_ids, attn_mask, clm_labels
+
     def round_batch(self,
                     x: torch.tensor,
                     lengths: torch.tensor):
@@ -269,7 +299,10 @@ class Distiller:
         if ml1 % 8 != 0:
             pad = 8 - (ml1 % 8)
             ml2 = ml1 + pad
+            if self.mlm:
                 pad_id = self.params.special_tok_ids['pad_token']
+            else:
+                pad_id = self.params.special_tok_ids['unk_token']
             padding_tensor = torch.zeros(bs2, pad, dtype=torch.long, device=x.device).fill_(pad_id)
             x = torch.cat([x, padding_tensor], 1)
             assert x.size() == (bs2, ml2)
@@ -292,14 +325,16 @@ class Distiller:
             if self.multi_gpu:
                 torch.distributed.barrier()
 
-            iter_bar = trange(self.num_steps_epoch, desc="-Iter", disable=self.params.local_rank not in [-1, 0])
-            for __ in range(self.num_steps_epoch):
-                batch = self.get_batch()
+            iter_bar = tqdm(self.dataloader, desc="-Iter", disable=self.params.local_rank not in [-1, 0])
+            for batch in iter_bar:
                 if self.params.n_gpu > 0:
                     batch = tuple(t.to(f'cuda:{self.params.local_rank}') for t in batch)
-                token_ids, attn_mask, mlm_labels = self.prepare_batch(batch=batch)
 
-                self.step(input_ids=token_ids, attention_mask=attn_mask, mlm_labels=mlm_labels)
+                if self.mlm:
+                    token_ids, attn_mask, lm_labels = self.prepare_batch_mlm(batch=batch)
+                else:
+                    token_ids, attn_mask, lm_labels = self.prepare_batch_clm(batch=batch)
+                self.step(input_ids=token_ids, attention_mask=attn_mask, lm_labels=lm_labels)
 
                 iter_bar.update()
                 iter_bar.set_postfix({'Last_loss': f'{self.last_loss:.2f}',
@@ -317,7 +352,7 @@ class Distiller:
     def step(self,
              input_ids: torch.tensor,
              attention_mask: torch.tensor,
-             mlm_labels: torch.tensor):
+             lm_labels: torch.tensor):
         """
         One optimization step: forward of student AND teacher, backward on the loss (for gradient accumulation),
         and possibly a parameter update (depending on the gradient accumulation).
@@ -326,17 +361,22 @@ class Distiller:
         ------
         input_ids: `torch.tensor(bs, seq_length)` - The token ids.
         attention_mask: `torch.tensor(bs, seq_length)` - The attention mask for self attention.
-        mlm_labels: `torch.tensor(bs, seq_length)` - The masked language modeling labels.
+        lm_labels: `torch.tensor(bs, seq_length)` - The language modeling labels (mlm labels for MLM and clm labels for CLM).
         """
+        if self.mlm:
             s_logits, s_hidden_states = self.student(input_ids=input_ids, attention_mask=attention_mask)     # (bs, seq_length, voc_size)
             with torch.no_grad():
                 t_logits, t_hidden_states = self.teacher(input_ids=input_ids, attention_mask=attention_mask) # (bs, seq_length, voc_size)
+        else:
+            s_logits, _, s_hidden_states = self.student(input_ids=input_ids, attention_mask=None)            # (bs, seq_length, voc_size)
+            with torch.no_grad():
+                t_logits, _, t_hidden_states = self.teacher(input_ids=input_ids, attention_mask=None)           # (bs, seq_length, voc_size)
         assert s_logits.size() == t_logits.size()
 
         #https://github.com/peterliht/knowledge-distillation-pytorch/blob/master/model/net.py#L100
         #https://github.com/peterliht/knowledge-distillation-pytorch/issues/2
         if self.params.restrict_ce_to_mask:
-            mask = (mlm_labels>-1).unsqueeze(-1).expand_as(s_logits)   # (bs, seq_lenth, voc_size)
+            mask = (lm_labels>-1).unsqueeze(-1).expand_as(s_logits)    # (bs, seq_lenth, voc_size)
         else:
             mask = attention_mask.unsqueeze(-1).expand_as(s_logits)    # (bs, seq_lenth, voc_size)
         s_logits_slct = torch.masked_select(s_logits, mask)            # (bs * seq_length * voc_size) modulo the 1s in mask
@@ -348,13 +388,20 @@ class Distiller:
         loss_ce = self.ce_loss_fct(F.log_softmax(s_logits_slct/self.temperature, dim=-1),
                                    F.softmax(t_logits_slct/self.temperature, dim=-1)) * (self.temperature)**2
         loss = self.alpha_ce*loss_ce
+
         if self.alpha_mlm > 0.:
-            loss_mlm = self.mlm_loss_fct(s_logits.view(-1, s_logits.size(-1)), mlm_labels.view(-1))
+            loss_mlm = self.lm_loss_fct(s_logits.view(-1, s_logits.size(-1)), lm_labels.view(-1))
             loss += self.alpha_mlm * loss_mlm
+        if self.alpha_clm > 0.:
+            shift_logits = s_logits[..., :-1, :].contiguous()
+            shift_labels = lm_labels[..., 1:].contiguous()
+            loss_clm = self.lm_loss_fct(shift_logits.view(-1, shift_logits.size(-1)),
+                                        shift_labels.view(-1))
+            loss += self.alpha_clm * loss_clm
+
         if self.alpha_mse > 0.:
             loss_mse = self.mse_loss_fct(s_logits_slct, t_logits_slct)/s_logits_slct.size(0) # Reproducing batchmean reduction
             loss += self.alpha_mse * loss_mse
-        
         if self.alpha_cos > 0.:
             s_hidden_states = s_hidden_states[-1]                              # (bs, seq_length, dim)
             t_hidden_states = t_hidden_states[-1]                              # (bs, seq_length, dim)
@@ -376,6 +423,8 @@ class Distiller:
         self.last_loss_ce = loss_ce.item()
         if self.alpha_mlm > 0.:
             self.last_loss_mlm = loss_mlm.item()
+        if self.alpha_clm > 0.:
+            self.last_loss_clm = loss_clm.item()
         if self.alpha_mse > 0.:
             self.last_loss_mse = loss_mse.item()
         if self.alpha_cos > 0.:
@@ -452,6 +501,8 @@ class Distiller:
         self.tensorboard.add_scalar(tag="losses/loss_ce", scalar_value=self.last_loss_ce, global_step=self.n_total_iter)
         if self.alpha_mlm > 0.:
             self.tensorboard.add_scalar(tag="losses/loss_mlm", scalar_value=self.last_loss_mlm, global_step=self.n_total_iter)
+        if self.alpha_clm > 0.:
+            self.tensorboard.add_scalar(tag="losses/loss_clm", scalar_value=self.last_loss_clm, global_step=self.n_total_iter)
         if self.alpha_mse > 0.:
             self.tensorboard.add_scalar(tag="losses/loss_mse", scalar_value=self.last_loss_mse, global_step=self.n_total_iter)
         if self.alpha_cos > 0.:

examples/distillation/grouped_batch_sampler.py

+# coding=utf-8
+# Copyright 2019-present, the HuggingFace Inc. team and Facebook, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+""" Adapted from PyTorch Vision (https://github.com/pytorch/vision/blob/master/references/detection/group_by_aspect_ratio.py)
+"""
+import bisect
+import copy
+from collections import defaultdict
+import numpy as np
+
+from torch.utils.data.sampler import BatchSampler, Sampler
+
+from utils import logger
+
+def _quantize(x, bins):
+    bins = copy.deepcopy(bins)
+    bins = sorted(bins)
+    quantized = list(map(lambda y: bisect.bisect_right(bins, y), x))
+    return quantized
+
+def create_lengths_groups(lengths, k=0):
+    bins = np.arange(start=3, stop=k, step=4).tolist() if k > 0 else [10]
+    groups = _quantize(lengths, bins)
+    # count number of elements per group
+    counts = np.unique(groups, return_counts=True)[1]
+    fbins = [0] + bins + [np.inf]
+    logger.info("Using {} as bins for aspect lengths quantization".format(fbins))
+    logger.info("Count of instances per bin: {}".format(counts))
+    return groups
+
+class GroupedBatchSampler(BatchSampler):
+    """
+    Wraps another sampler to yield a mini-batch of indices.
+    It enforces that the batch only contain elements from the same group.
+    It also tries to provide mini-batches which follows an ordering which is
+    as close as possible to the ordering from the original sampler.
+    Arguments:
+        sampler (Sampler): Base sampler.
+        group_ids (list[int]): If the sampler produces indices in range [0, N),
+            `group_ids` must be a list of `N` ints which contains the group id of each sample.
+            The group ids must be a continuous set of integers starting from
+            0, i.e. they must be in the range [0, num_groups).
+        batch_size (int): Size of mini-batch.
+    """
+    def __init__(self, sampler, group_ids, batch_size):
+        if not isinstance(sampler, Sampler):
+            raise ValueError(
+                "sampler should be an instance of "
+                "torch.utils.data.Sampler, but got sampler={}".format(sampler)
+            )
+        self.sampler = sampler
+        self.group_ids = group_ids
+        self.batch_size = batch_size
+
+    def __iter__(self):
+        buffer_per_group = defaultdict(list)
+        samples_per_group = defaultdict(list)
+
+        num_batches = 0
+        for idx in self.sampler:
+            group_id = self.group_ids[idx]
+            buffer_per_group[group_id].append(idx)
+            samples_per_group[group_id].append(idx)
+            if len(buffer_per_group[group_id]) == self.batch_size:
+                yield buffer_per_group[group_id] #TODO
+                num_batches += 1
+                del buffer_per_group[group_id]
+            assert len(buffer_per_group[group_id]) < self.batch_size
+
+        # now we have run out of elements that satisfy
+        # the group criteria, let's return the remaining
+        # elements so that the size of the sampler is
+        # deterministic
+        expected_num_batches = len(self)
+        num_remaining = expected_num_batches - num_batches
+        if num_remaining > 0:
+            # for the remaining batches, group the batches by similar lengths
+            batch_idx = []
+            for group_id, idxs in sorted(buffer_per_group.items(), key=lambda x: x[0]):
+                batch_idx.extend(idxs)
+                if len(batch_idx) >= self.batch_size:
+                    yield batch_idx[:self.batch_size]
+                    batch_idx = batch_idx[self.batch_size:]
+                    num_remaining -= 1
+            if len(batch_idx) > 0:
+                yield batch_idx
+                num_remaining -= 1
+        assert num_remaining == 0
+
+    def __len__(self):
+        """
+        Return the number of mini-batches rather than the number of samples.
+        """
+        return (len(self.sampler) + self.batch_size - 1) // self.batch_size

examples/distillation/dataset.py → examples/distillation/lm_seqs_dataset.py

@@ -12,30 +12,33 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-""" Dataloaders to train DistilBERT
+""" Dataset to distilled models
     adapted in part from Facebook, Inc XLM model (https://github.com/facebookresearch/XLM)
 """
-from typing import List
-import math
-from itertools import chain
-from collections import Counter
-import numpy as np
 import torch
+from torch.utils.data import Dataset
 
+import numpy as np
 from utils import logger
 
-class Dataset:
+class LmSeqsDataset(Dataset):
+    """Custom Dataset wrapping language modeling sequences.
+
+    Each sample will be retrieved by indexing the list of token_ids and their corresponding lengths.
+
+    Input:
+    ------
+        params: `NameSpace` parameters
+        data: `List[np.array[int]]
+    """
+
     def __init__(self,
                  params,
                  data):
         self.params = params
-        self.tokens_per_batch = params.tokens_per_batch
-        self.batch_size = params.batch_size
-        self.shuffle = params.shuffle
-        self.group_by_size = params.group_by_size
 
         self.token_ids = np.array(data)
-        self.lengths = np.uint16([len(t) for t in data])
+        self.lengths = np.array([len(t) for t in data])
 
         self.check()
         self.remove_long_sequences()
@@ -43,6 +46,9 @@ class Dataset:
         self.check()
         self.print_statistics()
 
+    def __getitem__(self, index):
+        return (self.token_ids[index], self.lengths[index])
+
     def __len__(self):
         return len(self.lengths)
 
@@ -51,12 +57,14 @@ class Dataset:
         Some sanity checks
         """
         assert len(self.token_ids) == len(self.lengths)
+        assert all(self.lengths[i] == len(self.token_ids[i]) for i in range(len(self.lengths))) 
 
     def remove_long_sequences(self):
         """
-        Sequences that are too long are splitted by chunk of max_position_embeddings.
+        Sequences that are too long are splitted by chunk of max_model_input_size.
         """
-        indices = self.lengths >= self.params.max_position_embeddings
+        max_len = self.params.max_model_input_size
+        indices = self.lengths > max_len
         logger.info(f'Splitting {sum(indices)} too long sequences.')
 
         def divide_chunks(l, n):
@@ -64,10 +72,13 @@ class Dataset:
 
         new_tok_ids = []
         new_lengths = []
+        if self.params.mlm:
             cls_id, sep_id = self.params.special_tok_ids['cls_token'], self.params.special_tok_ids['sep_token']
-        max_len = self.params.max_position_embeddings
+        else:
+            cls_id, sep_id = self.params.special_tok_ids['bos_token'], self.params.special_tok_ids['eos_token']
 
         for seq_, len_ in zip(self.token_ids, self.lengths):
+            assert (seq_[0] == cls_id) and (seq_[-1] == sep_id), seq_
             if len_ <= max_len:
                 new_tok_ids.append(seq_)
                 new_lengths.append(len_)
@@ -79,6 +90,7 @@ class Dataset:
                     if sub_s[-1] != sep_id:
                         sub_s = np.insert(sub_s, len(sub_s), sep_id)
                     assert len(sub_s) <= max_len
+                    assert (sub_s[0] == cls_id) and (sub_s[-1] == sep_id), sub_s
                     sub_seqs.append(sub_s)
 
                 new_tok_ids.extend(sub_seqs)
@@ -113,89 +125,27 @@ class Dataset:
         # nb_unkown = sum([(t==unk_idx).sum() for t in self.token_ids])
         # logger.info(f'{nb_unkown} unknown tokens (covering {100*nb_unkown/data_len:.2f}% of the data)')
 
-    def select_data(self, a: int, b: int):
-        """
-        Select a subportion of the data.
-        """
-        n_sequences = len(self)
-        assert 0 <= a < b <= n_sequences, ValueError(f'`0 <= a < b <= n_sequences` is not met with a={a} and b={b}')
-
-        logger.info(f'Selecting sequences from {a} to {b} (excluded).')
-        self.token_ids = self.token_ids[a:b]
-        self.lengths = self.lengths[a:b]
-
-        self.check()
-
-    def split(self):
-        """
-        Distributed training: split the data accross the processes.
-        """
-        assert self.params.n_gpu > 1
-        logger.info('Splitting the data accross the processuses.')
-        n_seq = len(self)
-        n_seq_per_procesus = n_seq // self.params.world_size
-        a = n_seq_per_procesus * self.params.global_rank
-        b = a + n_seq_per_procesus
-        self.select_data(a=a, b=b)
-
     def batch_sequences(self,
-                        token_ids: List[List[int]],
-                        lengths: List[int]):
+                        batch):
         """
         Do the padding and transform into torch.tensor.
         """
+        token_ids = [t[0] for t in batch]
+        lengths = [t[1] for t in batch]
         assert len(token_ids) == len(lengths)
 
         # Max for paddings
         max_seq_len_ = max(lengths)
 
         # Pad token ids
+        if self.params.mlm:
             pad_idx = self.params.special_tok_ids['pad_token']
+        else:
+            pad_idx = self.params.special_tok_ids['unk_token']
         tk_ = [list(t.astype(int)) + [pad_idx]*(max_seq_len_-len(t)) for t in token_ids]
         assert len(tk_) == len(token_ids)
         assert all(len(t) == max_seq_len_ for t in tk_)
 
         tk_t = torch.tensor(tk_)      # (bs, max_seq_len_)
-        lg_t = torch.tensor(lengths.astype(int))  # (bs)
+        lg_t = torch.tensor(lengths)  # (bs)
         return tk_t, lg_t
-
-    def get_batches_iterator(self,
-                             batches):
-        """
-        Return an iterator over batches.
-        """
-        for sequences_ids in batches:
-            token_ids, lengths = self.batch_sequences(self.token_ids[sequences_ids],
-                                                    self.lengths[sequences_ids])
-            yield (token_ids, lengths)
-
-    def get_iterator(self,
-                     seed: int = None):
-        """
-        Return a data iterator.
-        """
-        rng = np.random.RandomState(seed)
-
-        n_sequences = len(self)
-        indices = np.arange(n_sequences)
-
-        if self.group_by_size:
-            indices = indices[np.argsort(self.lengths[indices], kind='mergesort')]
-
-        if self.tokens_per_batch == -1:
-            batches = np.array_split(indices, math.ceil(len(indices) * 1. / self.batch_size))
-        else:
-            assert self.tokens_per_batch > 0
-            batch_ids = np.cumsum(self.lengths[indices]) // self.tokens_per_batch
-            _, bounds = np.unique(batch_ids, return_index=True)
-            batches = [indices[bounds[i]:bounds[i + 1]] for i in range(len(bounds) - 1)]
-            if bounds[-1] < len(indices):
-                batches.append(indices[bounds[-1]:])
-
-        if self.shuffle:
-            rng.shuffle(batches)
-
-        assert n_sequences == sum([len(x) for x in batches])
-        assert self.lengths[indices].sum() == sum([self.lengths[x].sum() for x in batches])
-
-        return self.get_batches_iterator(batches=batches)

examples/distillation/requirements.txt

@@ -3,4 +3,4 @@ tensorboard>=1.14.0
 tensorboardX==1.8
 psutil==5.6.3
 scipy==1.3.1
-pytorch_transformers==1.2.0
+transformers==2.0.0

examples/distillation/scripts/binarized_data.py

@@ -13,14 +13,14 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """
-Preprocessing script before training DistilBERT.
+Preprocessing script before distillation.
 """
 import argparse
 import pickle
 import random
 import time
 import numpy as np
-from transformers import BertTokenizer, RobertaTokenizer
+from transformers import BertTokenizer, RobertaTokenizer, GPT2Tokenizer
 import logging
 
 logging.basicConfig(format = '%(asctime)s - %(levelname)s - %(name)s -   %(message)s',
@@ -32,7 +32,7 @@ def main():
     parser = argparse.ArgumentParser(description="Preprocess the data to avoid re-doing it several times by (tokenization + token_to_ids).")
     parser.add_argument('--file_path', type=str, default='data/dump.txt',
                         help='The path to the data.')
-    parser.add_argument('--tokenizer_type', type=str, default='bert', choices=['bert', 'roberta'])
+    parser.add_argument('--tokenizer_type', type=str, default='bert', choices=['bert', 'roberta', 'gpt2'])
     parser.add_argument('--tokenizer_name', type=str, default='bert-base-uncased',
                         help="The tokenizer to use.")
     parser.add_argument('--dump_file', type=str, default='data/dump',
@@ -43,10 +43,16 @@ def main():
     logger.info(f'Loading Tokenizer ({args.tokenizer_name})')
     if args.tokenizer_type == 'bert':
         tokenizer = BertTokenizer.from_pretrained(args.tokenizer_name)
+        bos = tokenizer.special_tokens_map['cls_token'] # `[CLS]`
+        sep = tokenizer.special_tokens_map['sep_token'] # `[SEP]`
     elif args.tokenizer_type == 'roberta':
         tokenizer = RobertaTokenizer.from_pretrained(args.tokenizer_name)
-    bos = tokenizer.special_tokens_map['bos_token'] # `[CLS]` for bert, `<s>` for roberta
-    sep = tokenizer.special_tokens_map['sep_token'] # `[SEP]` for bert, `</s>` for roberta
+        bos = tokenizer.special_tokens_map['cls_token'] # `<s>`
+        sep = tokenizer.special_tokens_map['sep_token'] # `</s>`
+    elif args.tokenizer_type == 'gpt2':
+        tokenizer = GPT2Tokenizer.from_pretrained(args.tokenizer_name)
+        bos = tokenizer.special_tokens_map['bos_token'] # `<|endoftext|>`
+        sep = tokenizer.special_tokens_map['eos_token'] # `<|endoftext|>`    
 
     logger.info(f'Loading text from {args.file_path}')
     with open(args.file_path, 'r', encoding='utf8') as fp:

examples/distillation/scripts/extract.py

+# coding=utf-8
+# Copyright 2019-present, the HuggingFace Inc. team.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""
+Preprocessing script before training the distilled model.
+Specific to RoBERTa -> DistilRoBERTa and GPT2 -> DistilGPT2.
+"""
+from transformers import BertForMaskedLM, RobertaForMaskedLM, GPT2LMHeadModel
+import torch
+import argparse
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description="Extraction some layers of the full RobertaForMaskedLM or GPT2LMHeadModel for Transfer Learned Distillation")
+    parser.add_argument("--model_type", default="roberta", choices=["roberta", "gpt2"])
+    parser.add_argument("--model_name", default='roberta-large', type=str)
+    parser.add_argument("--dump_checkpoint", default='serialization_dir/tf_roberta_048131723.pth', type=str)
+    parser.add_argument("--vocab_transform", action='store_true')
+    args = parser.parse_args()
+
+
+    if args.model_type == 'roberta':
+        model = RobertaForMaskedLM.from_pretrained(args.model_name)
+        prefix = 'roberta'
+    elif args.model_type == 'gpt2':
+        model = GPT2LMHeadModel.from_pretrained(args.model_name)
+        prefix = 'transformer'
+
+    state_dict = model.state_dict()
+    compressed_sd = {}
+
+    ### Embeddings ###
+    if args.model_type == 'gpt2':
+        for param_name in ['wte.weight', 'wpe.weight']:
+            compressed_sd[f'{prefix}.{param_name}'] = state_dict[f'{prefix}.{param_name}']
+    else:
+        for w in ['word_embeddings', 'position_embeddings', 'token_type_embeddings']:
+            param_name = f'{prefix}.embeddings.{w}.weight'
+            compressed_sd[param_name] = state_dict[param_name]
+        for w in ['weight', 'bias']:
+            param_name = f'{prefix}.embeddings.LayerNorm.{w}'
+            compressed_sd[param_name] = state_dict[param_name]
+
+    ### Transformer Blocks ###
+    std_idx = 0
+    for teacher_idx in [0, 2, 4, 7, 9, 11]:
+        if args.model_type == 'gpt2':
+            for layer in ['ln_1', 'attn.c_attn', 'attn.c_proj', 'ln_2', 'mlp.c_fc', 'mlp.c_proj']:
+                for w in ['weight', 'bias']:
+                    compressed_sd[f'{prefix}.h.{std_idx}.{layer}.{w}'] = \
+                        state_dict[f'{prefix}.h.{teacher_idx}.{layer}.{w}']
+            compressed_sd[f'{prefix}.h.{std_idx}.attn.bias'] = state_dict[f'{prefix}.h.{teacher_idx}.attn.bias']
+        else:
+            for layer in ['attention.self.query', 'attention.self.key', 'attention.self.value',
+                        'attention.output.dense', 'attention.output.LayerNorm',
+                        'intermediate.dense', 'output.dense', 'output.LayerNorm']:
+                for w in ['weight', 'bias']:
+                    compressed_sd[f'{prefix}.encoder.layer.{std_idx}.{layer}.{w}'] = \
+                        state_dict[f'{prefix}.encoder.layer.{teacher_idx}.{layer}.{w}']
+        std_idx += 1
+
+    ### Language Modeling Head ###s
+    if args.model_type == 'roberta':
+        for layer in ['lm_head.decoder.weight', 'lm_head.bias']:
+            compressed_sd[f'{layer}'] = state_dict[f'{layer}']
+        if args.vocab_transform:
+            for w in ['weight', 'bias']:
+                compressed_sd[f'lm_head.dense.{w}'] = state_dict[f'lm_head.dense.{w}']
+                compressed_sd[f'lm_head.layer_norm.{w}'] = state_dict[f'lm_head.layer_norm.{w}']
+    elif args.model_type == 'gpt2':
+        for w in ['weight', 'bias']:
+            compressed_sd[f'{prefix}.ln_f.{w}'] = state_dict[f'{prefix}.ln_f.{w}']
+        compressed_sd[f'lm_head.weight'] = state_dict[f'lm_head.weight']
+
+    print(f'N layers selected for distillation: {std_idx}')
+    print(f'Number of params transfered for distillation: {len(compressed_sd.keys())}')
+
+    print(f'Save transfered checkpoint to {args.dump_checkpoint}.')
+    torch.save(compressed_sd, args.dump_checkpoint)

examples/distillation/scripts/extract_for_distil.py → examples/distillation/scripts/extract_distilbert.py

@@ -14,6 +14,7 @@
 # limitations under the License.
 """
 Preprocessing script before training DistilBERT.
+Specific to BERT -> DistilBERT.
 """
 from transformers import BertForMaskedLM, RobertaForMaskedLM
 import torch
@@ -21,7 +22,7 @@ import argparse
 
 if __name__ == '__main__':
     parser = argparse.ArgumentParser(description="Extraction some layers of the full BertForMaskedLM or RObertaForMaskedLM for Transfer Learned Distillation")
-    parser.add_argument("--model_type", default="bert", choices=["bert", "roberta"])
+    parser.add_argument("--model_type", default="bert", choices=["bert"])
     parser.add_argument("--model_name", default='bert-base-uncased', type=str)
     parser.add_argument("--dump_checkpoint", default='serialization_dir/tf_bert-base-uncased_0247911.pth', type=str)
     parser.add_argument("--vocab_transform", action='store_true')
@@ -31,9 +32,8 @@ if __name__ == '__main__':
     if args.model_type == 'bert':
         model = BertForMaskedLM.from_pretrained(args.model_name)
         prefix = 'bert'
-    elif args.model_type == 'roberta':
-        model = RobertaForMaskedLM.from_pretrained(args.model_name)
-        prefix = 'roberta'
+    else:
+        raise ValueError(f'args.model_type should be "bert".')
 
     state_dict = model.state_dict()
     compressed_sd = {}
@@ -68,20 +68,12 @@ if __name__ == '__main__':
                 state_dict[f'{prefix}.encoder.layer.{teacher_idx}.output.LayerNorm.{w}']
         std_idx += 1
 
-    if args.model_type == 'bert':
     compressed_sd[f'vocab_projector.weight'] = state_dict[f'cls.predictions.decoder.weight']
     compressed_sd[f'vocab_projector.bias'] = state_dict[f'cls.predictions.bias']
     if args.vocab_transform:
         for w in ['weight', 'bias']:
             compressed_sd[f'vocab_transform.{w}'] = state_dict[f'cls.predictions.transform.dense.{w}']
             compressed_sd[f'vocab_layer_norm.{w}'] = state_dict[f'cls.predictions.transform.LayerNorm.{w}']
-    elif args.model_type == 'roberta':
-        compressed_sd[f'vocab_projector.weight'] = state_dict[f'lm_head.decoder.weight']
-        compressed_sd[f'vocab_projector.bias'] = state_dict[f'lm_head.bias']
-        if args.vocab_transform:
-            for w in ['weight', 'bias']:
-                compressed_sd[f'vocab_transform.{w}'] = state_dict[f'lm_head.dense.{w}']
-                compressed_sd[f'vocab_layer_norm.{w}'] = state_dict[f'lm_head.layer_norm.{w}']
 
     print(f'N layers selected for distillation: {std_idx}')
     print(f'Number of params transfered for distillation: {len(compressed_sd.keys())}')

examples/distillation/scripts/token_counts.py

@@ -13,7 +13,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """
-Preprocessing script before training DistilBERT.
+Preprocessing script before training the distilled model.
 """
 from collections import Counter
 import argparse

examples/distillation/train.py

@@ -13,7 +13,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """
-Training DistilBERT.
+Training the distilled model.
+Supported architectures include: BERT -> DistilBERT, RoBERTa -> DistilRoBERTa, GPT2 -> DistilGPT2.
 """
 import os
 import argparse
@@ -23,68 +24,96 @@ import shutil
 import numpy as np
 import torch
 
-from transformers import BertTokenizer, BertForMaskedLM, RobertaTokenizer, RobertaForMaskedLM
-from transformers import DistilBertForMaskedLM, DistilBertConfig
+from transformers import BertConfig, BertForMaskedLM, BertTokenizer
+from transformers import RobertaConfig, RobertaForMaskedLM, RobertaTokenizer
+from transformers import DistilBertConfig, DistilBertForMaskedLM, DistilBertTokenizer
+from transformers import GPT2Config, GPT2LMHeadModel, GPT2Tokenizer
 
 from distiller import Distiller
 from utils import git_log, logger, init_gpu_params, set_seed
-from dataset import Dataset
+from lm_seqs_dataset import LmSeqsDataset
+
+
+MODEL_CLASSES = {
+    'distilbert': (DistilBertConfig, DistilBertForMaskedLM, DistilBertTokenizer),
+    'roberta': (RobertaConfig, RobertaForMaskedLM, RobertaTokenizer),
+    'bert': (BertConfig, BertForMaskedLM, BertTokenizer),
+    'gpt2': (GPT2Config, GPT2LMHeadModel, GPT2Tokenizer)
+}
+
+def sanity_checks(args):
+    """
+    A bunch of args sanity checks to perform even starting...
+    """
+    assert (args.mlm and args.alpha_mlm > 0.) or (not args.mlm and args.alpha_mlm == 0.)
+    assert (args.alpha_mlm > 0. and args.alpha_clm == 0.) or (args.alpha_mlm == 0. and args.alpha_clm > 0.)
+    if args.mlm:
+        assert os.path.isfile(args.token_counts)
+        assert (args.student_type in ['roberta', 'distilbert']) and (args.teacher_type in ['roberta', 'bert'])
+    else:
+        assert (args.student_type in ['gpt2']) and (args.teacher_type in ['gpt2'])
+
+    assert args.teacher_type == args.student_type or (args.student_type=='distilbert' and args.teacher_type=='bert')
+    assert os.path.isfile(args.student_config)
+    if args.student_pretrained_weights is not None:
+        assert os.path.isfile(args.student_pretrained_weights)
+
+    if args.freeze_token_type_embds: assert args.student_type in ['roberta']
+
+    assert args.alpha_ce >= 0.
+    assert args.alpha_mlm >= 0.
+    assert args.alpha_clm >= 0.
+    assert args.alpha_mse >= 0.
+    assert args.alpha_cos >= 0.
+    assert args.alpha_ce + args.alpha_mlm + args.alpha_clm + args.alpha_mse + args.alpha_cos > 0.
+
+def freeze_pos_embeddings(student, args):
+    if args.student_type == 'roberta':
+        student.roberta.embeddings.position_embeddings.weight.requires_grad = False
+    elif args.student_type == 'gpt2':
+        student.transformer.wpe.weight.requires_grad = False
 
+def freeze_token_type_embeddings(student, args):
+    if args.student_type == 'roberta':
+        student.roberta.embeddings.token_type_embeddings.weight.requires_grad = False
 
 def main():
     parser = argparse.ArgumentParser(description="Training")
+    parser.add_argument("--force", action='store_true',
+                        help="Overwrite dump_path if it already exists.")
 
     parser.add_argument("--dump_path", type=str, required=True,
                         help="The output directory (log, checkpoints, parameters, etc.)")
     parser.add_argument("--data_file", type=str, required=True,
                         help="The binarized file (tokenized + tokens_to_ids) and grouped by sequence.")
-    parser.add_argument("--token_counts", type=str, required=True,
-                        help="The token counts in the data_file for MLM.")
-    parser.add_argument("--force", action='store_true',
-                        help="Overwrite dump_path if it already exists.")
 
-    parser.add_argument("--vocab_size", default=30522, type=int,
-                        help="The vocabulary size.")
-    parser.add_argument("--max_position_embeddings", default=512, type=int,
-                        help="Maximum sequence length we can model (including [CLS] and [SEP]).")
-    parser.add_argument("--sinusoidal_pos_embds", action='store_false',
-                        help="If true, the position embeddings are simply fixed with sinusoidal embeddings.")
-    parser.add_argument("--n_layers", default=6, type=int,
-                        help="Number of Transformer blocks.")
-    parser.add_argument("--n_heads", default=12, type=int,
-                        help="Number of heads in the self-attention module.")
-    parser.add_argument("--dim", default=768, type=int,
-                        help="Dimension through the network. Must be divisible by n_heads")
-    parser.add_argument("--hidden_dim", default=3072, type=int,
-                        help="Intermediate dimension in the FFN.")
-    parser.add_argument("--dropout", default=0.1, type=float,
-                        help="Dropout.")
-    parser.add_argument("--attention_dropout", default=0.1, type=float,
-                        help="Dropout in self-attention.")
-    parser.add_argument("--activation", default='gelu', type=str,
-                        help="Activation to use in self-attention")
-    parser.add_argument("--tie_weights_", action='store_false',
-                        help="If true, we tie the embeddings matrix with the projection over the vocabulary matrix. Default is true.")
-
-    parser.add_argument("--from_pretrained_weights", default=None, type=str,
+    parser.add_argument("--student_type", type=str, choices=["distilbert", "roberta", "gpt2"], required=True,
+                        help="The student type (DistilBERT, RoBERTa).")
+    parser.add_argument("--student_config", type=str, required=True,
+                        help="Path to the student configuration.")
+    parser.add_argument("--student_pretrained_weights", default=None, type=str,
                         help="Load student initialization checkpoint.")
-    parser.add_argument("--from_pretrained_config", default=None, type=str,
-                        help="Load student initialization architecture config.")
-    parser.add_argument("--teacher_type", default="bert", choices=["bert", "roberta"],
+
+    parser.add_argument("--teacher_type", choices=["bert", "roberta", "gpt2"], required=True,
                         help="Teacher type (BERT, RoBERTa).")
-    parser.add_argument("--teacher_name", default="bert-base-uncased", type=str,
+    parser.add_argument("--teacher_name", type=str, required=True,
                         help="The teacher model.")
 
     parser.add_argument("--temperature", default=2., type=float,
                         help="Temperature for the softmax temperature.")
     parser.add_argument("--alpha_ce", default=0.5, type=float,
                         help="Linear weight for the distillation loss. Must be >=0.")
-    parser.add_argument("--alpha_mlm", default=0.5, type=float,
-                        help="Linear weight for the MLM loss. Must be >=0.")
+    parser.add_argument("--alpha_mlm", default=0.0, type=float,
+                        help="Linear weight for the MLM loss. Must be >=0. Should be used in coonjunction with `mlm` flag.")
+    parser.add_argument("--alpha_clm", default=0.5, type=float,
+                        help="Linear weight for the CLM loss. Must be >=0.")
     parser.add_argument("--alpha_mse", default=0.0, type=float,
                         help="Linear weight of the MSE loss. Must be >=0.")
     parser.add_argument("--alpha_cos", default=0.0, type=float,
                         help="Linear weight of the cosine embedding loss. Must be >=0.")
+
+    parser.add_argument("--mlm", action="store_true",
+                        help="The LM step: MLM or CLM. If `mlm` is True, the MLM is used over CLM.")
     parser.add_argument("--mlm_mask_prop", default=0.15, type=float,
                         help="Proportion of tokens for which we need to make a prediction.")
     parser.add_argument("--word_mask", default=0.8, type=float,
@@ -95,17 +124,20 @@ def main():
                         help="Proportion of tokens to randomly replace.")
     parser.add_argument("--mlm_smoothing", default=0.7, type=float,
                         help="Smoothing parameter to emphasize more rare tokens (see XLM, similar to word2vec).")
+    parser.add_argument("--token_counts", type=str,
+                        help="The token counts in the data_file for MLM.")
+
     parser.add_argument("--restrict_ce_to_mask", action='store_true',
                         help="If true, compute the distilation loss only the [MLM] prediction distribution.")
+    parser.add_argument("--freeze_pos_embs", action="store_true",
+                        help="Freeze positional embeddings during distillation. For student_type in ['roberta', 'gpt2'] only.")
+    parser.add_argument("--freeze_token_type_embds", action="store_true",
+                        help="Freeze token type embeddings during distillation if existent. For student_type in ['roberta'] only.")
 
     parser.add_argument("--n_epoch", type=int, default=3,
                         help="Number of pass on the whole dataset.")
     parser.add_argument("--batch_size", type=int, default=5,
                         help="Batch size (for each process).")
-    parser.add_argument("--tokens_per_batch", type=int, default=-1,
-                        help="If specified, modify the batches so that they have approximately this number of tokens.")
-    parser.add_argument("--shuffle", action='store_false',
-                        help="If true, shuffle the sequence order. Default is true.")
     parser.add_argument("--group_by_size", action='store_false',
                         help="If true, group sequences that have similar length into the same batch. Default is true.")
 
@@ -141,6 +173,7 @@ def main():
     parser.add_argument("--checkpoint_interval", type=int, default=4000,
                         help="Checkpoint interval.")
     args = parser.parse_args()
+    sanity_checks(args)
 
 
     ## ARGS ##
@@ -164,21 +197,19 @@ def main():
         with open(os.path.join(args.dump_path, 'parameters.json'), 'w') as f:
             json.dump(vars(args), f, indent=4)
         git_log(args.dump_path)
-    assert (args.from_pretrained_weights is None and args.from_pretrained_config is None) or \
-           (args.from_pretrained_weights is not None and args.from_pretrained_config is not None)
 
+    student_config_class, student_model_class, _ = MODEL_CLASSES[args.student_type]
+    teacher_config_class, teacher_model_class, teacher_tokenizer_class = MODEL_CLASSES[args.teacher_type]
 
     ### TOKENIZER ###
-    if args.teacher_type == 'bert':
-        tokenizer = BertTokenizer.from_pretrained(args.teacher_name)
-    elif args.teacher_type == 'roberta':
-        tokenizer = RobertaTokenizer.from_pretrained(args.teacher_name)
+    tokenizer = teacher_tokenizer_class.from_pretrained(args.teacher_name)
     special_tok_ids = {}
     for tok_name, tok_symbol in tokenizer.special_tokens_map.items():
         idx = tokenizer.all_special_tokens.index(tok_symbol)
         special_tok_ids[tok_name] = tokenizer.all_special_ids[idx]
     logger.info(f'Special tokens {special_tok_ids}')
     args.special_tok_ids = special_tok_ids
+    args.max_model_input_size = tokenizer.max_model_input_sizes[args.teacher_name]
 
 
     ## DATA LOADER ##
@@ -187,35 +218,34 @@ def main():
         data = pickle.load(fp)
 
 
-    assert os.path.isfile(args.token_counts)
+    if args.mlm:
         logger.info(f'Loading token counts from {args.token_counts} (already pre-computed)')
         with open(args.token_counts, 'rb') as fp:
             counts = pickle.load(fp)
-        assert len(counts) == args.vocab_size
+        
         token_probs = np.maximum(counts, 1) ** -args.mlm_smoothing
         for idx in special_tok_ids.values():
             token_probs[idx] = 0.  # do not predict special tokens
         token_probs = torch.from_numpy(token_probs)
+    else:
+        token_probs = None
 
 
-    train_dataloader = Dataset(params=args, data=data)
+    train_lm_seq_dataset = LmSeqsDataset(params=args, data=data)
     logger.info(f'Data loader created.')
 
 
     ## STUDENT ##
-    if args.from_pretrained_weights is not None:
-        assert os.path.isfile(args.from_pretrained_weights)
-        assert os.path.isfile(args.from_pretrained_config)
-        logger.info(f'Loading pretrained weights from {args.from_pretrained_weights}')
-        logger.info(f'Loading pretrained config from {args.from_pretrained_config}')
-        stu_architecture_config = DistilBertConfig.from_json_file(args.from_pretrained_config)
+    logger.info(f'Loading student config from {args.student_config}')
+    stu_architecture_config = student_config_class.from_pretrained(args.student_config)
     stu_architecture_config.output_hidden_states = True
-        student = DistilBertForMaskedLM.from_pretrained(args.from_pretrained_weights,
+
+    if args.student_pretrained_weights is not None:
+        logger.info(f'Loading pretrained weights from {args.student_pretrained_weights}')
+        student = student_model_class.from_pretrained(args.student_pretrained_weights,
                                                       config=stu_architecture_config)
     else:
-        args.vocab_size_or_config_json_file = args.vocab_size
-        stu_architecture_config = DistilBertConfig(**vars(args), output_hidden_states=True)
-        student = DistilBertForMaskedLM(stu_architecture_config)
+        student = student_model_class(stu_architecture_config)
 
 
     if args.n_gpu > 0:
@@ -224,18 +254,31 @@ def main():
 
 
     ## TEACHER ##
-    if args.teacher_type == 'bert':
-        teacher = BertForMaskedLM.from_pretrained(args.teacher_name, output_hidden_states=True)
-    elif args.teacher_type == 'roberta':
-        teacher = RobertaForMaskedLM.from_pretrained(args.teacher_name, output_hidden_states=True)
+    teacher = teacher_model_class.from_pretrained(args.teacher_name, output_hidden_states=True)
     if args.n_gpu > 0:
         teacher.to(f'cuda:{args.local_rank}')
     logger.info(f'Teacher loaded from {args.teacher_name}.')
 
+
+    ## FREEZING ##
+    if args.freeze_pos_embs:
+        freeze_pos_embeddings(student, args)
+    if args.freeze_token_type_embds:
+        freeze_token_type_embeddings(student, args)
+
+
+    ## SANITY CHECKS ##
+    assert student.config.vocab_size == teacher.config.vocab_size
+    assert student.config.hidden_size == teacher.config.hidden_size
+    assert student.config.max_position_embeddings == teacher.config.max_position_embeddings
+    if args.mlm:
+        assert token_probs.size(0) == stu_architecture_config.vocab_size
+
+
     ## DISTILLER ##
     torch.cuda.empty_cache()
     distiller = Distiller(params=args,
-                          dataloader=train_dataloader,
+                          dataset=train_lm_seq_dataset,
                           token_probs=token_probs,
                           student=student,
                           teacher=teacher)

examples/distillation/training_configs/distilbert-base-uncased.json

+{
+	"activation": "gelu",
+	"attention_dropout": 0.1,
+	"dim": 768,
+	"dropout": 0.1,
+	"hidden_dim": 3072,
+	"initializer_range": 0.02,
+	"max_position_embeddings": 512,
+	"n_heads": 12,
+	"n_layers": 6,
+	"sinusoidal_pos_embds": true,
+	"tie_weights_": true,
+	"vocab_size": 30522
+  }
+  
\ No newline at end of file

examples/distillation/training_configs/distilgpt2.json

+{
+	"initializer_range": 0.02,
+	"layer_norm_epsilon": 0.00001,
+	"n_ctx": 1024,
+	"n_embd": 768,
+	"n_head": 12,
+	"n_layer": 6,
+	"n_positions": 1024,
+	"vocab_size": 50257
+}
\ No newline at end of file

examples/requirements.txt

 tensorboardX
+tensorboard
 scikit-learn
+seqeval

examples/run_generation.py

@@ -14,7 +14,7 @@
 # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 # See the License for the specific language governing permissions and
 # limitations under the License.
-""" Conditional text generation with the auto-regressive models of the library (GPT/GPT-2/Transformer-XL/XLNet)
+""" Conditional text generation with the auto-regressive models of the library (GPT/GPT-2/CTRL/Transformer-XL/XLNet)
 """
 from __future__ import absolute_import, division, print_function, unicode_literals
 
@@ -26,12 +26,14 @@ import torch
 import torch.nn.functional as F
 import numpy as np
 
-from transformers import GPT2Config, OpenAIGPTConfig, XLNetConfig, TransfoXLConfig
+from transformers import GPT2Config, OpenAIGPTConfig, XLNetConfig, TransfoXLConfig, XLMConfig, CTRLConfig
 
 from transformers import GPT2LMHeadModel, GPT2Tokenizer
 from transformers import OpenAIGPTLMHeadModel, OpenAIGPTTokenizer
 from transformers import XLNetLMHeadModel, XLNetTokenizer
 from transformers import TransfoXLLMHeadModel, TransfoXLTokenizer
+from transformers import CTRLLMHeadModel, CTRLTokenizer
+from transformers import XLMWithLMHeadModel, XLMTokenizer
 
 
 logging.basicConfig(format = '%(asctime)s - %(levelname)s - %(name)s -   %(message)s',
@@ -41,13 +43,15 @@ logger = logging.getLogger(__name__)
 
 MAX_LENGTH = int(10000)  # Hardcoded max length to avoid infinite loop
 
-ALL_MODELS = sum((tuple(conf.pretrained_config_archive_map.keys()) for conf in (GPT2Config, OpenAIGPTConfig, XLNetConfig, TransfoXLConfig)), ())
+ALL_MODELS = sum((tuple(conf.pretrained_config_archive_map.keys()) for conf in (GPT2Config, OpenAIGPTConfig, XLNetConfig, TransfoXLConfig, XLMConfig, CTRLConfig)), ())
 
 MODEL_CLASSES = {
     'gpt2': (GPT2LMHeadModel, GPT2Tokenizer),
+    'ctrl': (CTRLLMHeadModel, CTRLTokenizer),
     'openai-gpt': (OpenAIGPTLMHeadModel, OpenAIGPTTokenizer),
     'xlnet': (XLNetLMHeadModel, XLNetTokenizer),
     'transfo-xl': (TransfoXLLMHeadModel, TransfoXLTokenizer),
+    'xlm': (XLMWithLMHeadModel, XLMTokenizer),
 }
 
 # Padding text to help Transformer-XL and XLNet with short prompts as proposed by Aman Rusia
@@ -103,7 +107,8 @@ def top_k_top_p_filtering(logits, top_k=0, top_p=0.0, filter_value=-float('Inf')
     return logits
 
 
-def sample_sequence(model, length, context, num_samples=1, temperature=1, top_k=0, top_p=0.0, is_xlnet=False, device='cpu'):
+def sample_sequence(model, length, context, num_samples=1, temperature=1, top_k=0, top_p=0.0, repetition_penalty=1.0,
+                    is_xlnet=False, is_xlm_mlm=False, xlm_mask_token=None, xlm_lang=None, device='cpu'):
     context = torch.tensor(context, dtype=torch.long, device=device)
     context = context.unsqueeze(0).repeat(num_samples, 1)
     generated = context
@@ -121,9 +126,26 @@ def sample_sequence(model, length, context, num_samples=1, temperature=1, top_k=
                 target_mapping[0, 0, -1] = 1.0  # predict last token
                 inputs = {'input_ids': input_ids, 'perm_mask': perm_mask, 'target_mapping': target_mapping}
 
-            outputs = model(**inputs)  # Note: we could also use 'past' with GPT-2/Transfo-XL/XLNet (cached hidden-states)
-            next_token_logits = outputs[0][0, -1, :] / temperature
+            if is_xlm_mlm and xlm_mask_token:
+                # XLM MLM models are direct models (predict same token, not next token)
+                # => need one additional dummy token in the input (will be masked and guessed)
+                input_ids = torch.cat((generated, torch.full((1, 1), xlm_mask_token, dtype=torch.long, device=device)), dim=1)
+                inputs = {'input_ids': input_ids}
+
+            if xlm_lang is not None:
+                inputs["langs"] = torch.tensor([xlm_lang] * inputs["input_ids"].shape[1], device=device).view(1, -1)
+
+            outputs = model(**inputs)  # Note: we could also use 'past' with GPT-2/Transfo-XL/XLNet/CTRL (cached hidden-states)
+            next_token_logits = outputs[0][0, -1, :] / (temperature if temperature > 0 else 1.)
+
+            # reptition penalty from CTRL (https://arxiv.org/abs/1909.05858)
+            for _ in set(generated.view(-1).tolist()):
+                next_token_logits[_] /= repetition_penalty
+                
             filtered_logits = top_k_top_p_filtering(next_token_logits, top_k=top_k, top_p=top_p)
+            if temperature == 0: #greedy sampling:
+                next_token = torch.argmax(filtered_logits).unsqueeze(0)
+            else:
                 next_token = torch.multinomial(F.softmax(filtered_logits, dim=-1), num_samples=1)
             generated = torch.cat((generated, next_token.unsqueeze(0)), dim=1)
     return generated
@@ -137,14 +159,20 @@ def main():
                         help="Path to pre-trained model or shortcut name selected in the list: " + ", ".join(ALL_MODELS))
     parser.add_argument("--prompt", type=str, default="")
     parser.add_argument("--padding_text", type=str, default="")
+    parser.add_argument("--xlm_lang", type=str, default="", help="Optional language when used with the XLM model.")
     parser.add_argument("--length", type=int, default=20)
-    parser.add_argument("--temperature", type=float, default=1.0)
+    parser.add_argument("--temperature", type=float, default=1.0,
+                        help="temperature of 0 implies greedy sampling")
+    parser.add_argument("--repetition_penalty", type=float, default=1.0,
+                        help="primarily useful for CTRL model; in that case, use 1.2")
     parser.add_argument("--top_k", type=int, default=0)
     parser.add_argument("--top_p", type=float, default=0.9)
     parser.add_argument("--no_cuda", action='store_true',
                         help="Avoid using CUDA when available")
     parser.add_argument('--seed', type=int, default=42,
                         help="random seed for initialization")
+    parser.add_argument('--stop_token', type=str, default=None,
+                        help="Token at which text generation is stopped")
     args = parser.parse_args()
 
     args.device = torch.device("cuda" if torch.cuda.is_available() and not args.no_cuda else "cpu")
@@ -166,8 +194,31 @@ def main():
     elif args.length < 0:
         args.length = MAX_LENGTH  # avoid infinite loop
 
-    print(args)
+    logger.info(args)
+    if args.model_type in ["ctrl"]:
+        if args.temperature > 0.7 : 
+            logger.info('CTRL typically works better with lower temperatures (and lower top_k).')
+
     while True:
+        xlm_lang = None
+        # XLM Language usage detailed in the issues #1414
+        if args.model_type in ["xlm"] and hasattr(tokenizer, 'lang2id') and hasattr(model.config, 'use_lang_emb') \
+                and model.config.use_lang_emb:
+            if args.xlm_lang:
+                language = args.xlm_lang
+            else:
+                language = None
+                while language not in tokenizer.lang2id.keys():
+                    language = input("Using XLM. Select language in " + str(list(tokenizer.lang2id.keys())) + " >>> ")
+            xlm_lang = tokenizer.lang2id[language]
+
+        # XLM masked-language modeling (MLM) models need masked token (see details in sample_sequence)
+        is_xlm_mlm = args.model_type in ["xlm"] and 'mlm' in args.model_name_or_path
+        if is_xlm_mlm:
+            xlm_mask_token = tokenizer.mask_token_id
+        else:
+            xlm_mask_token = None
+
         raw_text = args.prompt if args.prompt else input("Model prompt >>> ")
         if args.model_type in ["transfo-xl", "xlnet"]:
             # Models with memory likes to have a long prompt for short inputs.
@@ -180,11 +231,18 @@ def main():
             temperature=args.temperature,
             top_k=args.top_k,
             top_p=args.top_p,
-            device=args.device,
+            repetition_penalty=args.repetition_penalty,
             is_xlnet=bool(args.model_type == "xlnet"),
+            is_xlm_mlm=is_xlm_mlm,
+            xlm_mask_token=xlm_mask_token,
+            xlm_lang=xlm_lang,
+            device=args.device,
         )
         out = out[0, len(context_tokens):].tolist()
-        text = tokenizer.decode(out, clean_up_tokenization_spaces=True)
+
+        text = tokenizer.decode(out, clean_up_tokenization_spaces=True, skip_special_tokens=True)
+        text = text[: text.find(args.stop_token) if args.stop_token else None]
+
         print(text)
         if args.prompt:
             break

examples/run_glue.py

@@ -28,7 +28,12 @@ import torch
 from torch.utils.data import (DataLoader, RandomSampler, SequentialSampler,
                               TensorDataset)
 from torch.utils.data.distributed import DistributedSampler
-from tensorboardX import SummaryWriter
+
+try:
+    from torch.utils.tensorboard import SummaryWriter
+except:
+    from tensorboardX import SummaryWriter
+
 from tqdm import tqdm, trange
 
 from transformers import (WEIGHTS_NAME, BertConfig,
@@ -53,7 +58,8 @@ from transformers import glue_convert_examples_to_features as convert_examples_t
 
 logger = logging.getLogger(__name__)
 
-ALL_MODELS = sum((tuple(conf.pretrained_config_archive_map.keys()) for conf in (BertConfig, XLNetConfig, XLMConfig, RobertaConfig)), ())
+ALL_MODELS = sum((tuple(conf.pretrained_config_archive_map.keys()) for conf in (BertConfig, XLNetConfig, XLMConfig, 
+                                                                                RobertaConfig, DistilBertConfig)), ())
 
 MODEL_CLASSES = {
     'bert': (BertConfig, BertForSequenceClassification, BertTokenizer),
@@ -154,7 +160,7 @@ def train(args, train_dataset, model, tokenizer):
                 torch.nn.utils.clip_grad_norm_(model.parameters(), args.max_grad_norm)
 
             tr_loss += loss.item()
-            if (step + 1) % args.gradient_accumulation_steps == 0:
+            if (step + 1) % args.gradient_accumulation_steps == 0 and not args.tpu:
                 optimizer.step()
                 scheduler.step()  # Update learning rate schedule
                 model.zero_grad()
@@ -180,6 +186,11 @@ def train(args, train_dataset, model, tokenizer):
                     torch.save(args, os.path.join(output_dir, 'training_args.bin'))
                     logger.info("Saving model checkpoint to %s", output_dir)
 
+            if args.tpu:
+                args.xla_model.optimizer_step(optimizer, barrier=True)
+                model.zero_grad()
+                global_step += 1
+
             if args.max_steps > 0 and global_step > args.max_steps:
                 epoch_iterator.close()
                 break
@@ -248,7 +259,7 @@ def evaluate(args, model, tokenizer, prefix=""):
         result = compute_metrics(eval_task, preds, out_label_ids)
         results.update(result)
 
-        output_eval_file = os.path.join(eval_output_dir, "eval_results.txt")
+        output_eval_file = os.path.join(eval_output_dir, prefix, "eval_results.txt")
         with open(output_eval_file, "w") as writer:
             logger.info("***** Eval results {} *****".format(prefix))
             for key in sorted(result.keys()):
@@ -270,7 +281,7 @@ def load_and_cache_examples(args, task, tokenizer, evaluate=False):
         list(filter(None, args.model_name_or_path.split('/'))).pop(),
         str(args.max_seq_length),
         str(task)))
-    if os.path.exists(cached_features_file):
+    if os.path.exists(cached_features_file) and not args.overwrite_cache:
         logger.info("Loading features from cached file %s", cached_features_file)
         features = torch.load(cached_features_file)
     else:
@@ -379,6 +390,15 @@ def main():
     parser.add_argument('--seed', type=int, default=42,
                         help="random seed for initialization")
 
+    parser.add_argument('--tpu', action='store_true',
+                        help="Whether to run on the TPU defined in the environment variables")
+    parser.add_argument('--tpu_ip_address', type=str, default='',
+                        help="TPU IP address if none are set in the environment variables")
+    parser.add_argument('--tpu_name', type=str, default='',
+                        help="TPU name if none are set in the environment variables")
+    parser.add_argument('--xrt_tpu_config', type=str, default='',
+                        help="XRT TPU config if none are set in the environment variables")
+
     parser.add_argument('--fp16', action='store_true',
                         help="Whether to use 16-bit (mixed) precision (through NVIDIA apex) instead of 32-bit")
     parser.add_argument('--fp16_opt_level', type=str, default='O1',
@@ -412,6 +432,23 @@ def main():
         args.n_gpu = 1
     args.device = device
 
+    if args.tpu:
+        if args.tpu_ip_address:
+            os.environ["TPU_IP_ADDRESS"] = args.tpu_ip_address
+        if args.tpu_name:
+            os.environ["TPU_NAME"] = args.tpu_name
+        if args.xrt_tpu_config:
+            os.environ["XRT_TPU_CONFIG"] = args.xrt_tpu_config
+
+        assert "TPU_IP_ADDRESS" in os.environ
+        assert "TPU_NAME" in os.environ
+        assert "XRT_TPU_CONFIG" in os.environ
+
+        import torch_xla
+        import torch_xla.core.xla_model as xm
+        args.device = xm.xla_device()
+        args.xla_model = xm
+
     # Setup logging
     logging.basicConfig(format = '%(asctime)s - %(levelname)s - %(name)s -   %(message)s',
                         datefmt = '%m/%d/%Y %H:%M:%S',
@@ -457,7 +494,7 @@ def main():
 
 
     # Saving best-practices: if you use defaults names for the model, you can reload it using from_pretrained()
-    if args.do_train and (args.local_rank == -1 or torch.distributed.get_rank() == 0):
+    if args.do_train and (args.local_rank == -1 or torch.distributed.get_rank() == 0) and not args.tpu:
         # Create output directory if needed
         if not os.path.exists(args.output_dir) and args.local_rank in [-1, 0]:
             os.makedirs(args.output_dir)
@@ -489,9 +526,11 @@ def main():
         logger.info("Evaluate the following checkpoints: %s", checkpoints)
         for checkpoint in checkpoints:
             global_step = checkpoint.split('-')[-1] if len(checkpoints) > 1 else ""
+            prefix = checkpoint.split('/')[-1] if checkpoint.find('checkpoint') != -1 else ""
+            
             model = model_class.from_pretrained(checkpoint)
             model.to(args.device)
-            result = evaluate(args, model, tokenizer, prefix=global_step)
+            result = evaluate(args, model, tokenizer, prefix=prefix)
             result = dict((k + '_{}'.format(global_step), v) for k, v in result.items())
             results.update(result)
 

examples/run_lm_finetuning.py

@@ -27,12 +27,19 @@ import logging
 import os
 import pickle
 import random
+import re
+import shutil
 
 import numpy as np
 import torch
 from torch.utils.data import DataLoader, Dataset, SequentialSampler, RandomSampler
 from torch.utils.data.distributed import DistributedSampler
-from tensorboardX import SummaryWriter
+
+try:
+    from torch.utils.tensorboard import SummaryWriter
+except:
+    from tensorboardX import SummaryWriter
+
 from tqdm import tqdm, trange
 
 from transformers import (WEIGHTS_NAME, AdamW, WarmupLinearSchedule,
@@ -59,7 +66,7 @@ class TextDataset(Dataset):
     def __init__(self, tokenizer, file_path='train', block_size=512):
         assert os.path.isfile(file_path)
         directory, filename = os.path.split(file_path)
-        cached_features_file = os.path.join(directory, 'cached_lm_{}_{}'.format(block_size, filename))
+        cached_features_file = os.path.join(directory, 'cached_lm_' + str(block_size) + '_' + filename)
 
         if os.path.exists(cached_features_file):
             logger.info("Loading features from cached file %s", cached_features_file)
@@ -75,7 +82,7 @@ class TextDataset(Dataset):
             tokenized_text = tokenizer.convert_tokens_to_ids(tokenizer.tokenize(text))
 
             for i in range(0, len(tokenized_text)-block_size+1, block_size): # Truncate in block of block_size
-                self.examples.append(tokenizer.add_special_tokens_single_sequence(tokenized_text[i:i+block_size]))
+                self.examples.append(tokenizer.build_inputs_with_special_tokens(tokenized_text[i:i+block_size]))
             # Note that we are loosing the last truncated example here for the sake of simplicity (no padding)
             # If your dataset is small, first you should loook for a bigger one :-) and second you
             # can change this behavior by adding (model specific) padding.
@@ -104,11 +111,43 @@ def set_seed(args):
         torch.cuda.manual_seed_all(args.seed)
 
 
+def _rotate_checkpoints(args, checkpoint_prefix, use_mtime=False):
+    if not args.save_total_limit:
+        return
+    if args.save_total_limit <= 0:
+        return
+
+    # Check if we should delete older checkpoint(s)
+    glob_checkpoints = glob.glob(os.path.join(args.output_dir, '{}-*'.format(checkpoint_prefix)))
+    if len(glob_checkpoints) <= args.save_total_limit:
+        return
+
+    ordering_and_checkpoint_path = []
+    for path in glob_checkpoints:
+        if use_mtime:
+            ordering_and_checkpoint_path.append((os.path.getmtime(path), path))
+        else:
+            regex_match = re.match('.*{}-([0-9]+)'.format(checkpoint_prefix), path)
+            if regex_match and regex_match.groups():
+                ordering_and_checkpoint_path.append((int(regex_match.groups()[0]), path))
+
+    checkpoints_sorted = sorted(ordering_and_checkpoint_path)
+    checkpoints_sorted = [checkpoint[1] for checkpoint in checkpoints_sorted]
+    number_of_checkpoints_to_delete = max(0, len(checkpoints_sorted) - args.save_total_limit)
+    checkpoints_to_be_deleted = checkpoints_sorted[:number_of_checkpoints_to_delete]
+    for checkpoint in checkpoints_to_be_deleted:
+        logger.info("Deleting older checkpoint [{}] due to args.save_total_limit".format(checkpoint))
+        shutil.rmtree(checkpoint)
+
+
 def mask_tokens(inputs, tokenizer, args):
     """ Prepare masked tokens inputs/labels for masked language modeling: 80% MASK, 10% random, 10% original. """
     labels = inputs.clone()
     # We sample a few tokens in each sequence for masked-LM training (with probability args.mlm_probability defaults to 0.15 in Bert/RoBERTa)
-    masked_indices = torch.bernoulli(torch.full(labels.shape, args.mlm_probability)).bool()
+    probability_matrix = torch.full(labels.shape, args.mlm_probability)
+    special_tokens_mask = [tokenizer.get_special_tokens_mask(val, already_has_special_tokens=True) for val in labels.tolist()]
+    probability_matrix.masked_fill_(torch.tensor(special_tokens_mask, dtype=torch.bool), value=0.0)
+    masked_indices = torch.bernoulli(probability_matrix).bool()
     labels[~masked_indices] = -1  # We only compute loss on masked tokens
 
     # 80% of the time, we replace masked input tokens with tokenizer.mask_token ([MASK])
@@ -222,8 +261,9 @@ def train(args, train_dataset, model, tokenizer):
                     logging_loss = tr_loss
 
                 if args.local_rank in [-1, 0] and args.save_steps > 0 and global_step % args.save_steps == 0:
+                    checkpoint_prefix = 'checkpoint'
                     # Save model checkpoint
-                    output_dir = os.path.join(args.output_dir, 'checkpoint-{}'.format(global_step))
+                    output_dir = os.path.join(args.output_dir, '{}-{}'.format(checkpoint_prefix, global_step))
                     if not os.path.exists(output_dir):
                         os.makedirs(output_dir)
                     model_to_save = model.module if hasattr(model, 'module') else model  # Take care of distributed/parallel training
@@ -231,6 +271,8 @@ def train(args, train_dataset, model, tokenizer):
                     torch.save(args, os.path.join(output_dir, 'training_args.bin'))
                     logger.info("Saving model checkpoint to %s", output_dir)
 
+                    _rotate_checkpoints(args, checkpoint_prefix)
+
             if args.max_steps > 0 and global_step > args.max_steps:
                 epoch_iterator.close()
                 break
@@ -282,7 +324,7 @@ def evaluate(args, model, tokenizer, prefix=""):
         "perplexity": perplexity
     }
 
-    output_eval_file = os.path.join(eval_output_dir, "eval_results.txt")
+    output_eval_file = os.path.join(eval_output_dir, prefix, "eval_results.txt")
     with open(output_eval_file, "w") as writer:
         logger.info("***** Eval results {} *****".format(prefix))
         for key in sorted(result.keys()):
@@ -359,6 +401,8 @@ def main():
                         help="Log every X updates steps.")
     parser.add_argument('--save_steps', type=int, default=50,
                         help="Save checkpoint every X updates steps.")
+    parser.add_argument('--save_total_limit', type=int, default=None,
+                        help='Limit the total amount of checkpoints, delete the older checkpoints in the output_dir, does not delete by default')
     parser.add_argument("--eval_all_checkpoints", action='store_true',
                         help="Evaluate all checkpoints starting with the same prefix as model_name_or_path ending and ending with step number")
     parser.add_argument("--no_cuda", action='store_true',
@@ -484,9 +528,11 @@ def main():
         logger.info("Evaluate the following checkpoints: %s", checkpoints)
         for checkpoint in checkpoints:
             global_step = checkpoint.split('-')[-1] if len(checkpoints) > 1 else ""
+            prefix = checkpoint.split('/')[-1] if checkpoint.find('checkpoint') != -1 else ""
+            
             model = model_class.from_pretrained(checkpoint)
             model.to(args.device)
-            result = evaluate(args, model, tokenizer, prefix=global_step)
+            result = evaluate(args, model, tokenizer, prefix=prefix)
             result = dict((k + '_{}'.format(global_step), v) for k, v in result.items())
             results.update(result)