def test_train_eval_change():
# Check that ShardedDDP handles the switch from training to eval properly
dist.init_process_group(init_method="file://" + tempfile.mkstemp()[1],
backend="gloo",
rank=0,
world_size=1)
model = _get_mlp()
model.train()
optimizer = OSS(params=model.parameters(),
optim=torch.optim.SGD,
lr=1e-3,
momentum=0.99)
model = ShardedDataParallel(model, optimizer)
input_tensor = torch.rand((2, 2))
loss = model(input_tensor).sum()
loss.backward() # make sure that the gradients are reduced
# Wipe the gradients and switch to eval mode
model.zero_grad()
model.eval()
_ = model(input_tensor)
assert next(model.parameters()).grad is None or torch.norm(
next(model.parameters()).grad) < 1e-6
# Get back to training
model = model.train()
model(input_tensor).sum().backward()
assert torch.norm(next(model.parameters()).grad) > 0.0
dist.destroy_process_group()
def train(args, *, tbl):
cfg, tokenizer, _, _ = nlp.models.bert.get_pretrained_bert(args.model_name, load_backbone=False,
load_mlm=False)
cfg = nlp.torch.models.bert.BertModel.get_cfg().clone_merge(cfg)
model = nlp.torch.models.bert.QTBertForPretrain(cfg)
model.to(args.device)
if args.start_step:
logging.info('Restart training from {}'.format(args.start_step))
parameters_option(args.start_step, model, args, 'Loading')
else:
model.apply(nlp.torch.models.bert.init_weights)
writer = None
if args.local_rank in (-1, 0):
writer = SummaryWriter(log_dir=os.path.join(args.ckpt_dir, 'tensorboard'))
# pin_memory=False due to lack of https://github.com/pytorch/pytorch/commit/54ce171f16c8859f829dde09f87c364c8a6b4130
sampler = RandomSampler(tbl) if args.local_rank == -1 else DistributedSampler(
tbl, seed=args.seed)
# batch_size // 2 for QuickThought
train_dataloader = DataLoader(np.arange(len(tbl)), sampler=sampler,
collate_fn=functools.partial(collate_fn, args=args, tbl=tbl),
batch_size=args.batch_size // 2,
num_workers=args.num_dataloader_workers, pin_memory=True)
no_decay = ['bias', 'LayerNorm.weight']
optimizer_grouped_parameters = [{
'params': [p for n, p in model.named_parameters() if not any(nd in n for nd in no_decay)],
'weight_decay':
args.weight_decay
}, {
'params': [p for n, p in model.named_parameters() if any(nd in n for nd in no_decay)],
'weight_decay':
0.0
}]
optimizer_arguments = {"lr": args.lr}
if get_world_size(args) > 1 and args.ZeRO:
optimizer = OSS(params=model.parameters(), optim=nlp.torch.optimizers.FusedLANS,
**optimizer_arguments)
model = ShardedDataParallel(model, optimizer)
elif get_world_size(args) > 1:
optimizer = nlp.torch.optimizers.FusedLANS(optimizer_grouped_parameters,
**optimizer_arguments)
model = DistributedDataParallel(model, device_ids=[args.local_rank],
output_device=args.local_rank, find_unused_parameters=True)
else:
optimizer = nlp.torch.optimizers.FusedLANS(optimizer_grouped_parameters,
**optimizer_arguments)
save_interval = args.ckpt_interval
logging.info(f'#Total Training Steps={args.num_steps}, '
f'Warmup Steps={args.warmup_ratio * args.num_steps}, '
f'Save Interval={save_interval}')
scheduler = nlp.torch.optimizers.schedules.get_warmup_linear_const_decay_poly_schedule(
optimizer, total_steps=args.num_steps, warmup_ratio=args.warmup_ratio,
const_ratio=args.const_ratio)
if args.start_step:
logging.info(f'Restart training from {args.start_step}')
states_option(args.start_step, optimizer, args, 'Loading')
ce_loss_fn = th.nn.CrossEntropyLoss()
step_num = args.start_step
if args.phase2:
step_num -= args.phase1_num_steps
running_num_tks, running_grad_norm = 0, 0
running_mlm_loss, running_qt_loss, running_mlm_acc, running_qt_acc = 0, 0, 0, 0
train_start_time = time.time()
tic = time.time()
model.zero_grad()
if get_world_size(args) > 1 and args.ZeRO:
scaler = ShardedGradScaler() if args.fp16 else None
else:
scaler = th.cuda.amp.GradScaler() if args.fp16 else None
train_iter = repeat(train_dataloader, set_epoch=args.local_rank != -1)
while step_num < args.num_steps:
step_num += 1
for accum_step in range(args.num_accumulated):
(input_id, segment_id, valid_length, mlm_positions, mlm_labels) = next(train_iter)
(input_id, segment_id, valid_length, mlm_positions,
mlm_labels) = (arr.to(args.device) for arr in next(train_iter))
model.train()
accumulation = ((accum_step + 1) % args.num_accumulated != 0)
with model.no_sync() if get_world_size(args) > 1 and accumulation else suppress():
with th.cuda.amp.autocast(enabled=args.fp16):
_, pooled_out, mlm_scores, qt_similarity = model(input_id, segment_id,
valid_length, mlm_positions)
mlm_loss = ce_loss_fn(mlm_scores, mlm_labels)
qt_label = th.arange(len(input_id) // 2, device=args.device)
qt_loss = ce_loss_fn(qt_similarity, qt_label)
loss = mlm_loss + qt_loss
if args.num_accumulated > 1:
loss = loss / args.num_accumulated
if args.fp16:
scaler.scale(loss).backward()
else:
loss.backward()
with th.no_grad():
qt_acc = (qt_similarity.argmax(dim=1) == qt_label).sum() / (len(input_id) // 2)
mlm_acc = (mlm_scores.argmax(dim=1) == mlm_labels).sum() / len(mlm_labels)
# Gather information from all workers for accurate statistics
reduced_num_tokens = valid_length.sum()
if get_world_size(args) > 1:
distributed.all_reduce(reduced_num_tokens)
reduced_num_mlm_tokens = th.tensor(len(mlm_labels), device=args.device)
if get_world_size(args) > 1:
distributed.all_reduce(reduced_num_mlm_tokens)
reduced_loss_mlm = mlm_loss.detach().clone() * len(mlm_labels) / reduced_num_mlm_tokens
if get_world_size(args) > 1:
distributed.all_reduce(reduced_loss_mlm)
reduced_acc_mlm = mlm_acc.detach().clone() * len(mlm_labels) / reduced_num_mlm_tokens
if get_world_size(args) > 1:
distributed.all_reduce(reduced_acc_mlm)
reduced_bs = th.tensor(len(input_id), device=args.device)
if get_world_size(args) > 1:
distributed.all_reduce(reduced_bs)
reduced_loss_qt = qt_loss.detach().clone() * len(input_id) / reduced_bs
if get_world_size(args) > 1:
distributed.all_reduce(reduced_loss_qt)
reduced_acc_qt = qt_acc.detach().clone() * len(input_id) / reduced_bs
if get_world_size(args) > 1:
distributed.all_reduce(reduced_acc_qt)
running_num_tks += reduced_num_tokens.item()
running_mlm_loss += reduced_loss_mlm.item()
running_mlm_acc += reduced_acc_mlm.item()
running_qt_loss += reduced_loss_qt.item()
running_qt_acc += reduced_acc_qt.item()
if not accumulation:
if args.fp16:
scaler.unscale_(optimizer) # unscale for gradient clipping
if get_world_size(args) > 1 and args.ZeRO:
total_norm = optimizer.clip_grad_norm(args.max_grad_norm)
else:
total_norm = th.nn.utils.clip_grad_norm_(model.parameters(), args.max_grad_norm)
if get_world_size(args) > 1:
distributed.all_reduce(total_norm)
total_norm /= get_world_size(args)
running_grad_norm += total_norm
if args.fp16:
scaler.step(optimizer)
scaler.update()
else:
optimizer.step()
with warnings.catch_warnings():
# Scheduler may warn if optimizer.step() call is skipped
# due to invalid gradients detected by scaler.
warnings.simplefilter("ignore", UserWarning)
scheduler.step()
optimizer.zero_grad(set_to_none=True)
if step_num % args.log_interval == 0:
toc = time.time()
wps = running_num_tks / (toc - tic)
eta = (args.num_steps - step_num) / (step_num / (toc - train_start_time)) / 3600
interval = args.log_interval * args.num_accumulated
logging.info(f'[Step {step_num}], LR={scheduler.get_last_lr()[0]:.6f}, '
f'Loss MLM/QT={running_mlm_loss / interval:.4f}/'
f'{running_qt_loss / interval:.4f}, '
f'Acc MLM/QT={running_mlm_acc / interval:.4f}/'
f'{running_qt_acc / interval:.4f}, '
f'Grad_norm={running_grad_norm / interval:.4f}, '
f'Time cost={toc - tic:.2f}, '
f'Throughput={wps:.2f} tokens/s, ETA={eta:.2f}h')
if args.local_rank in (-1, 0):
writer.add_scalar('Throughput_wps', wps, step_num)
writer.add_scalar('Loss/MLM', running_mlm_loss / interval, step_num)
writer.add_scalar('Loss/QT', running_qt_loss / interval, step_num)
writer.add_scalar('Acc/MLM', running_mlm_acc / interval, step_num)
writer.add_scalar('Acc/QT', running_qt_acc / interval, step_num)
writer.add_scalar('LR', scheduler.get_last_lr()[0], step_num)
writer.add_scalar('Grad_norm', running_grad_norm / interval, step_num)
running_num_tks, running_grad_norm = 0, 0
running_mlm_loss, running_qt_loss, running_mlm_acc, running_qt_acc = 0, 0, 0, 0
tic = time.time()
# Saving
if step_num % save_interval == 0 or step_num >= args.num_steps:
states_option(step_num, optimizer, args, 'Saving')
if args.local_rank in (0, -1):
parameters_option(step_num, model, args, 'Saving')
logging.info('Finish training step: %d', step_num)
train_end_time = time.time()
logging.info('Train cost={:.1f} s'.format(train_end_time - train_start_time))
if args.local_rank in (0, -1):
save_dir = os.path.join(args.ckpt_dir, args.model_name)
final_save(model, save_dir, tokenizer.vocab, cfg)
