trainer.py
determine epochs
如果能拿到dataset length,则立刻改变Train epochs
# trainer.py #2205
if has_length(train_dataloader):
len_dataloader = len(train_dataloader)
num_update_steps_per_epoch = len_dataloader // args.gradient_accumulation_steps
num_update_steps_per_epoch = max(num_update_steps_per_epoch, 1)
num_examples = self.num_examples(train_dataloader)
if args.max_steps > 0:
max_steps = args.max_steps
num_train_epochs = args.max_steps // num_update_steps_per_epoch + int(
args.max_steps % num_update_steps_per_epoch > 0
)
# May be slightly incorrect if the last batch in the training dataloader has a smaller size but it's
# the best we can do.
num_train_samples = args.max_steps * total_train_batch_size
if args.include_tokens_per_second:
num_train_tokens = (
self.num_tokens(train_dataloader, args.max_steps) * args.gradient_accumulation_steps
)
else:
max_steps = math.ceil(args.num_train_epochs * num_update_steps_per_epoch)
num_train_epochs = math.ceil(args.num_train_epochs)
num_train_samples = self.num_examples(train_dataloader) * args.num_train_epochs
if args.include_tokens_per_second:
num_train_tokens = self.num_tokens(train_dataloader) * args.num_train_epochs
elif args.max_steps > 0: # Rely on max_steps when dataloader does not have a working size
max_steps = args.max_steps
# Setting a very large number of epochs so we go as many times as necessary over the iterator.
num_train_epochs = sys.maxsize
num_update_steps_per_epoch = max_steps
num_examples = total_train_batch_size * args.max_steps
num_train_samples = args.max_steps * total_train_batch_size
if args.include_tokens_per_second:
num_train_tokens = self.num_tokens(train_dataloader, args.max_steps) * args.gradient_accumulation_steps