def __init__(self, model_path):
super(OnmtGPT2Encoder, self).__init__()
config = GPT2Config.from_json_file(
os.path.join(model_path, "config.json"))
pretrained_dict = os.path.join(model_path, "pytorch_model.bin")
if os.path.exists(pretrained_dict):
model = GPT2Model.from_pretrained(
pretrained_model_name_or_path=pretrained_dict, config=config)
print("init GPT2 model with {} weights".format(
len(model.state_dict())))
else:
model = GPT2Model(config)
model.wte = expandEmbeddingByN(model.wte, 4)
self.encoder = model
#print(model)
print("***" * 20)
def convert_gpt2_checkpoint_to_pytorch(gpt2_checkpoint_path, gpt2_config_file,
pytorch_dump_folder_path):
# Construct model
if gpt2_config_file == "":
config = GPT2Config()
else:
config = GPT2Config.from_json_file(gpt2_config_file)
model = GPT2Model(config)
# Load weights from numpy
load_tf_weights_in_gpt2(model, config, gpt2_checkpoint_path)
# Save pytorch-model
pytorch_weights_dump_path = pytorch_dump_folder_path + '/' + WEIGHTS_NAME
pytorch_config_dump_path = pytorch_dump_folder_path + '/' + CONFIG_NAME
print("Save PyTorch model to {}".format(pytorch_weights_dump_path))
torch.save(model.state_dict(), pytorch_weights_dump_path)
print("Save configuration file to {}".format(pytorch_config_dump_path))
with open(pytorch_config_dump_path, "w", encoding="utf-8") as f:
f.write(config.to_json_string())
def train():
parser = ArgumentParser()
parser.add_argument(
"--dataset_path",
type=str,
default="",
help="Path or url of the dataset. If empty download from S3.")
parser.add_argument("--dataset_file",
type=str,
default="",
help="the dataset file. If empty download from S3.")
parser.add_argument("--dataset_cache",
type=str,
default='./dataset_cache',
help="Path or url of the dataset cache")
parser.add_argument("--model_checkpoint",
type=str,
default="openai-gpt",
help="Path, url or short name of the model")
parser.add_argument("--is_local_model",
type=bool,
default=False,
help="If True, it will load model from local")
parser.add_argument("--num_candidates",
type=int,
default=2,
help="Number of candidates for training")
parser.add_argument("--max_history",
type=int,
default=2,
help="Number of previous exchanges to keep in history")
parser.add_argument("--train_batch_size",
type=int,
default=4,
help="Batch size for training")
parser.add_argument("--valid_batch_size",
type=int,
default=4,
help="Batch size for validation")
parser.add_argument("--gradient_accumulation_steps",
type=int,
default=8,
help="Accumulate gradients on several steps")
parser.add_argument("--lr",
type=float,
default=6.25e-5,
help="Learning rate")
parser.add_argument("--lm_coef",
type=float,
default=1.0,
help="LM loss coefficient")
parser.add_argument("--mc_coef",
type=float,
default=1.0,
help="Multiple-choice loss coefficient")
parser.add_argument("--max_norm",
type=float,
default=1.0,
help="Clipping gradient norm")
parser.add_argument("--n_epochs",
type=int,
default=3,
help="Number of training epochs")
parser.add_argument("--personality_permutations",
type=int,
default=1,
help="Number of permutations of personality sentences")
parser.add_argument(
"--eval_before_start",
action='store_true',
help="If true start with a first evaluation before training")
parser.add_argument("--device",
type=str,
default="cuda" if torch.cuda.is_available() else "cpu",
help="Device (cuda or cpu)")
parser.add_argument(
"--fp16",
type=str,
default="",
help=
"Set to O0, O1, O2 or O3 for fp16 training (see apex documentation)")
parser.add_argument(
"--local_rank",
type=int,
default=-1,
help="Local rank for distributed training (-1: not distributed)")
args = parser.parse_args()
# logging is set to INFO (resp. WARN) for main (resp. auxiliary) process. logger.info => log main process only, logger.warning => log all processes
logging.basicConfig(
level=logging.INFO if args.local_rank in [-1, 0] else logging.WARN)
logger.warning(
"Running process %d", args.local_rank
) # This is a logger.warning: it will be printed by all distributed processes
logger.info("Arguments: %s", pformat(args))
# Initialize distributed training if needed
args.distributed = (args.local_rank != -1)
if args.distributed:
torch.cuda.set_device(args.local_rank)
args.device = torch.device("cuda", args.local_rank)
torch.distributed.init_process_group(backend='nccl',
init_method='env://')
if args.is_local_model:
vocab_file = os.path.join(args.model_checkpoint, "gpt2-vocab.json")
merges_file = os.path.join(args.model_checkpoint, "gpt2-merges.txt")
logger.info("Load vocab_file: {}, merges_file: {}".format(
vocab_file, merges_file))
tokenizer = GPT2Tokenizer(vocab_file=vocab_file,
merges_file=merges_file)
config_file = os.path.join(args.model_checkpoint, "gpt2-config.json")
config = GPT2Config.from_json_file(json_file=config_file)
model = GPT2DoubleHeadsModel.from_pretrained(args.model_checkpoint,
from_tf=False,
config=config)
else:
logger.info("Prepare tokenizer, pretrained model and optimizer.")
tokenizer_class = GPT2Tokenizer if "gpt2" in args.model_checkpoint else OpenAIGPTTokenizer # cant use Autotokenizer because checkpoint could be a Path
tokenizer = tokenizer_class.from_pretrained(args.model_checkpoint)
model_class = GPT2DoubleHeadsModel if "gpt2" in args.model_checkpoint else OpenAIGPTDoubleHeadsModel
model = model_class.from_pretrained(args.model_checkpoint)
model.to(args.device)
# Add special tokens if they are not already added
add_special_tokens_(model, tokenizer)
optimizer = AdamW(model.parameters(), lr=args.lr, correct_bias=True)
# Prepare model for FP16 and distributed training if needed (order is important, distributed should be the last)
if args.fp16:
from apex import amp # Apex is only required if we use fp16 training
model, optimizer = amp.initialize(model,
optimizer,
opt_level=args.fp16)
if args.distributed:
model = DistributedDataParallel(model,
device_ids=[args.local_rank],
output_device=args.local_rank)
logger.info("Prepare datasets")
train_loader, val_loader, train_sampler, valid_sampler = get_data_loaders(
args, tokenizer)
# Training function and trainer
def update(engine, batch):
model.train()
batch = tuple(input_tensor.to(args.device) for input_tensor in batch)
input_ids, mc_token_ids, lm_labels, mc_labels, token_type_ids = batch
(lm_loss), (mc_loss), *_ = model(input_ids,
token_type_ids=token_type_ids,
mc_token_ids=mc_token_ids,
mc_labels=mc_labels,
lm_labels=lm_labels)
loss = (lm_loss * args.lm_coef +
mc_loss * args.mc_coef) / args.gradient_accumulation_steps
if args.fp16:
with amp.scale_loss(loss, optimizer) as scaled_loss:
scaled_loss.backward()
torch.nn.utils.clip_grad_norm_(amp.master_params(optimizer),
args.max_norm)
else:
loss.backward()
torch.nn.utils.clip_grad_norm_(model.parameters(), args.max_norm)
if engine.state.iteration % args.gradient_accumulation_steps == 0:
optimizer.step()
optimizer.zero_grad()
return loss.item()
trainer = Engine(update)
# Evaluation function and evaluator (evaluator output is the input of the metrics)
def inference(engine, batch):
model.eval()
with torch.no_grad():
batch = tuple(
input_tensor.to(args.device) for input_tensor in batch)
input_ids, mc_token_ids, lm_labels, mc_labels, token_type_ids = batch
logger.info(tokenizer.decode(input_ids[0, -1, :].tolist()))
# if we dont send labels to model, it doesnt return losses
lm_logits, mc_logits, *_ = model(
input_ids,
token_type_ids=token_type_ids,
mc_token_ids=mc_token_ids,
)
lm_logits_flat_shifted = lm_logits[..., :-1, :].contiguous().view(
-1, lm_logits.size(-1))
lm_labels_flat_shifted = lm_labels[..., 1:].contiguous().view(-1)
return (lm_logits_flat_shifted,
mc_logits), (lm_labels_flat_shifted, mc_labels)
evaluator = Engine(inference)
# Attach evaluation to trainer: we evaluate when we start the training and at the end of each epoch
trainer.add_event_handler(Events.EPOCH_COMPLETED,
lambda _: evaluator.run(val_loader))
if args.n_epochs < 1:
trainer.add_event_handler(Events.COMPLETED,
lambda _: evaluator.run(val_loader))
if args.eval_before_start:
trainer.add_event_handler(Events.STARTED,
lambda _: evaluator.run(val_loader))
# Make sure distributed data samplers split the dataset nicely between the distributed processes
if args.distributed:
trainer.add_event_handler(
Events.EPOCH_STARTED,
lambda engine: train_sampler.set_epoch(engine.state.epoch))
evaluator.add_event_handler(
Events.EPOCH_STARTED,
lambda engine: valid_sampler.set_epoch(engine.state.epoch))
# Linearly decrease the learning rate from lr to zero
scheduler = PiecewiseLinear(optimizer, "lr",
[(0, args.lr),
(args.n_epochs * len(train_loader), 0.0)])
trainer.add_event_handler(Events.ITERATION_STARTED, scheduler)
# Prepare metrics - note how we compute distributed metrics
RunningAverage(output_transform=lambda x: x).attach(trainer, "loss")
metrics = {
"nll":
Loss(torch.nn.CrossEntropyLoss(ignore_index=-1),
output_transform=lambda x: (x[0][0], x[1][0])),
"accuracy":
Accuracy(output_transform=lambda x: (x[0][1], x[1][1]))
}
metrics.update({
"average_nll":
MetricsLambda(average_distributed_scalar, metrics["nll"], args),
"average_accuracy":
MetricsLambda(average_distributed_scalar, metrics["accuracy"], args)
})
metrics["average_ppl"] = MetricsLambda(math.exp, metrics["average_nll"])
for name, metric in metrics.items():
metric.attach(evaluator, name)
# On the main process: add progress bar, tensorboard, checkpoints and save model, configuration and tokenizer before we start to train
if args.local_rank in [-1, 0]:
pbar = ProgressBar(persist=True)
pbar.attach(trainer, metric_names=["loss"])
evaluator.add_event_handler(
Events.COMPLETED, lambda _: pbar.log_message(
"Validation: %s" % pformat(evaluator.state.metrics)))
log_dir = make_logdir(args.model_checkpoint)
tb_logger = TensorboardLogger(log_dir)
tb_logger.attach(trainer,
log_handler=OutputHandler(tag="training",
metric_names=["loss"]),
event_name=Events.ITERATION_COMPLETED)
tb_logger.attach(trainer,
log_handler=OptimizerParamsHandler(optimizer),
event_name=Events.ITERATION_STARTED)
tb_logger.attach(evaluator,
log_handler=OutputHandler(tag="validation",
metric_names=list(
metrics.keys()),
another_engine=trainer),
event_name=Events.EPOCH_COMPLETED)
checkpoint_handler = ModelCheckpoint(log_dir,
'checkpoint',
save_interval=1,
n_saved=3)
trainer.add_event_handler(
Events.EPOCH_COMPLETED, checkpoint_handler,
{'mymodel': getattr(model, 'module', model)
}) # "getattr" takes care of distributed encapsulation
torch.save(args, log_dir + '/model_training_args.bin')
getattr(model, 'module',
model).config.to_json_file(os.path.join(log_dir, CONFIG_NAME))
tokenizer.save_pretrained(log_dir)
# Run the training
trainer.run(train_loader, max_epochs=args.n_epochs)
# On the main process: close tensorboard logger and rename the last checkpoint (for easy re-loading with OpenAIGPTModel.from_pretrained method)
if args.local_rank in [-1, 0] and args.n_epochs > 0:
os.rename(
checkpoint_handler._saved[-1][1][-1],
os.path.join(log_dir, WEIGHTS_NAME)
) # TODO: PR in ignite to have better access to saved file paths (cleaner)
tb_logger.close()