def validate(
cfg: DictConfig,
trainer: Trainer,
task: tasks.FairseqTask,
epoch_itr,
subsets: List[str],
) -> List[Optional[float]]:
"""Evaluate the model on the validation set(s) and return the losses."""
if cfg.dataset.fixed_validation_seed is not None:
# set fixed seed for every validation
utils.set_torch_seed(cfg.dataset.fixed_validation_seed)
trainer.begin_valid_epoch(epoch_itr.epoch)
valid_losses = []
for subset in subsets:
logger.info('begin validation on "{}" subset'.format(subset))
# Initialize data iterator
itr = trainer.get_valid_iterator(subset).next_epoch_itr(
shuffle=False, set_dataset_epoch=False # use a fixed valid set
)
if cfg.common.tpu:
itr = utils.tpu_data_loader(itr)
progress = progress_bar.progress_bar(
itr,
log_format=cfg.common.log_format,
log_interval=cfg.common.log_interval,
epoch=epoch_itr.epoch,
prefix=f"valid on '{subset}' subset",
tensorboard_logdir=(
cfg.common.tensorboard_logdir
if distributed_utils.is_master(cfg.distributed_training)
else None
),
default_log_format=("tqdm" if not cfg.common.no_progress_bar else "simple"),
wandb_project=(
cfg.common.wandb_project
if distributed_utils.is_master(cfg.distributed_training)
else None
),
wandb_run_name=os.environ.get(
"WANDB_NAME", os.path.basename(cfg.checkpoint.save_dir)
),
)
# create a new root metrics aggregator so validation metrics
# don't pollute other aggregators (e.g., train meters)
with metrics.aggregate(new_root=True) as agg:
for i, sample in enumerate(progress):
if cfg.dataset.max_valid_steps is not None and i > cfg.dataset.max_valid_steps:
break
trainer.valid_step(sample)
# log validation stats
stats = get_valid_stats(cfg, trainer, agg.get_smoothed_values())
progress.print(stats, tag=subset, step=trainer.get_num_updates())
valid_losses.append(stats[cfg.checkpoint.best_checkpoint_metric])
return valid_losses
def main(cfg: FairseqConfig) -> None:
if isinstance(cfg, argparse.Namespace):
cfg = convert_namespace_to_omegaconf(cfg)
utils.import_user_module(cfg.common)
if distributed_utils.is_master(
cfg.distributed_training) and "job_logging_cfg" in cfg:
# make hydra logging work with ddp (see # see https://github.com/facebookresearch/hydra/issues/1126)
logging.config.dictConfig(OmegaConf.to_container(cfg.job_logging_cfg))
assert (
cfg.dataset.max_tokens is not None
or cfg.dataset.batch_size is not None
), "Must specify batch size either with --max-tokens or --batch-size"
metrics.reset()
np.random.seed(cfg.common.seed)
utils.set_torch_seed(cfg.common.seed)
if distributed_utils.is_master(cfg.distributed_training):
checkpoint_utils.verify_checkpoint_directory(cfg.checkpoint.save_dir)
# Print args
logger.info(cfg)
if cfg.checkpoint.write_checkpoints_asynchronously:
try:
import iopath # noqa: F401
except ImportError:
logging.exception(
"Asynchronous checkpoint writing is specified but iopath is "
"not installed: `pip install iopath`")
return
# Setup task, e.g., translation, language modeling, etc.
task = tasks.setup_task(cfg.task)
assert cfg.criterion, "Please specify criterion to train a model"
# Build model and criterion
if cfg.distributed_training.ddp_backend == "fully_sharded":
with fsdp_enable_wrap(cfg.distributed_training):
model = fsdp_wrap(task.build_model(cfg.model))
else:
model = task.build_model(cfg.model)
criterion = task.build_criterion(cfg.criterion)
logger.info(model)
logger.info("task: {}".format(task.__class__.__name__))
logger.info("model: {}".format(model.__class__.__name__))
logger.info("criterion: {}".format(criterion.__class__.__name__))
logger.info("num. shared model params: {:,} (num. trained: {:,})".format(
sum(p.numel() for p in model.parameters()
if not getattr(p, "expert", False)),
sum(p.numel() for p in model.parameters()
if not getattr(p, "expert", False) and p.requires_grad)))
logger.info("num. expert model params: {} (num. trained: {})".format(
sum(p.numel() for p in model.parameters()
if getattr(p, "expert", False)),
sum(p.numel() for p in model.parameters()
if getattr(p, "expert", False) and p.requires_grad),
))
# Load valid dataset (we load training data below, based on the latest checkpoint)
# We load the valid dataset AFTER building the model
for valid_sub_split in cfg.dataset.valid_subset.split(","):
task.load_dataset(valid_sub_split, combine=False, epoch=1)
# (optionally) Configure quantization
if cfg.common.quantization_config_path is not None:
quantizer = quantization_utils.Quantizer(
config_path=cfg.common.quantization_config_path,
max_epoch=cfg.optimization.max_epoch,
max_update=cfg.optimization.max_update,
)
else:
quantizer = None
# Build trainer
if cfg.common.model_parallel_size == 1:
trainer = Trainer(cfg, task, model, criterion, quantizer)
else:
trainer = MegatronTrainer(cfg, task, model, criterion)
logger.info("training on {} devices (GPUs/TPUs)".format(
cfg.distributed_training.distributed_world_size))
logger.info(
"max tokens per device = {} and max sentences per device = {}".format(
cfg.dataset.max_tokens,
cfg.dataset.batch_size,
))
# Load the latest checkpoint if one is available and restore the
# corresponding train iterator
extra_state, epoch_itr = checkpoint_utils.load_checkpoint(
cfg.checkpoint,
trainer,
# don't cache epoch iterators for sharded datasets
disable_iterator_cache=task.has_sharded_data("train"),
)
if cfg.common.tpu:
import torch_xla.core.xla_model as xm
xm.rendezvous("load_checkpoint") # wait for all workers
max_epoch = cfg.optimization.max_epoch or math.inf
lr = trainer.get_lr()
train_meter = meters.StopwatchMeter()
train_meter.start()
while epoch_itr.next_epoch_idx <= max_epoch:
if lr <= cfg.optimization.stop_min_lr:
logger.info(
f"stopping training because current learning rate ({lr}) is smaller "
"than or equal to minimum learning rate "
f"(--stop-min-lr={cfg.optimization.stop_min_lr})")
break
# train for one epoch
valid_losses, should_stop = train(cfg, trainer, task, epoch_itr)
if should_stop:
break
# only use first validation loss to update the learning rate
lr = trainer.lr_step(epoch_itr.epoch, valid_losses[0])
epoch_itr = trainer.get_train_iterator(
epoch_itr.next_epoch_idx,
# sharded data: get train iterator for next epoch
load_dataset=task.has_sharded_data("train"),
# don't cache epoch iterators for sharded datasets
disable_iterator_cache=task.has_sharded_data("train"),
)
train_meter.stop()
logger.info("done training in {:.1f} seconds".format(train_meter.sum))
# ioPath implementation to wait for all asynchronous file writes to complete.
if cfg.checkpoint.write_checkpoints_asynchronously:
logger.info(
"ioPath PathManager waiting for all asynchronous checkpoint "
"writes to finish.")
PathManager.async_close()
logger.info("ioPath PathManager finished waiting.")
def train(cfg: DictConfig, trainer: Trainer, task: tasks.FairseqTask,
epoch_itr) -> Tuple[List[Optional[float]], bool]:
"""Train the model for one epoch and return validation losses."""
# Initialize data iterator
itr = epoch_itr.next_epoch_itr(
fix_batches_to_gpus=cfg.distributed_training.fix_batches_to_gpus,
shuffle=(epoch_itr.next_epoch_idx > cfg.dataset.curriculum),
)
update_freq = (cfg.optimization.update_freq[epoch_itr.epoch - 1]
if epoch_itr.epoch <= len(cfg.optimization.update_freq) else
cfg.optimization.update_freq[-1])
itr = iterators.GroupedIterator(itr, update_freq)
if cfg.common.tpu:
itr = utils.tpu_data_loader(itr)
progress = progress_bar.progress_bar(
itr,
log_format=cfg.common.log_format,
log_interval=cfg.common.log_interval,
epoch=epoch_itr.epoch,
tensorboard_logdir=(cfg.common.tensorboard_logdir
if distributed_utils.is_master(
cfg.distributed_training) else None),
default_log_format=("tqdm"
if not cfg.common.no_progress_bar else "simple"),
wandb_project=(cfg.common.wandb_project if distributed_utils.is_master(
cfg.distributed_training) else None),
wandb_run_name=os.environ.get(
"WANDB_NAME", os.path.basename(cfg.checkpoint.save_dir)),
azureml_logging=(cfg.common.azureml_logging
if distributed_utils.is_master(
cfg.distributed_training) else False),
)
progress.update_config(_flatten_config(cfg))
trainer.begin_epoch(epoch_itr.epoch)
valid_subsets = cfg.dataset.valid_subset.split(",")
should_stop = False
num_updates = trainer.get_num_updates()
logger.info("Start iterating over samples")
for i, samples in enumerate(progress):
with metrics.aggregate(
"train_inner"), torch.autograd.profiler.record_function(
"train_step-%d" % i):
log_output = trainer.train_step(samples)
if log_output is not None: # not OOM, overflow, ...
# log mid-epoch stats
num_updates = trainer.get_num_updates()
if num_updates % cfg.common.log_interval == 0:
stats = get_training_stats(
metrics.get_smoothed_values("train_inner"))
progress.log(stats, tag="train_inner", step=num_updates)
# reset mid-epoch stats after each log interval
# the end-of-epoch stats will still be preserved
metrics.reset_meters("train_inner")
end_of_epoch = not itr.has_next()
valid_losses, should_stop = validate_and_save(cfg, trainer, task,
epoch_itr, valid_subsets,
end_of_epoch)
if should_stop:
break
# log end-of-epoch stats
logger.info("end of epoch {} (average epoch stats below)".format(
epoch_itr.epoch))
stats = get_training_stats(metrics.get_smoothed_values("train"))
progress.print(stats, tag="train", step=num_updates)
# reset epoch-level meters
metrics.reset_meters("train")
return valid_losses, should_stop