class Seq2SeqTrainer:
"""
Seq2SeqTrainer
"""
def __init__(self,
model,
criterion,
opt_config,
scheduler_config,
print_freq=10,
save_freq=1000,
grad_clip=float('inf'),
batch_first=False,
save_info={},
save_path='.',
train_iterations=0,
checkpoint_filename='checkpoint%s.pth',
keep_checkpoints=5,
math='fp32',
cuda=True,
distributed=False,
intra_epoch_eval=0,
iter_size=1,
translator=None,
verbose=False):
"""
Constructor for the Seq2SeqTrainer.
:param model: model to train
:param criterion: criterion (loss function)
:param opt_config: dictionary with options for the optimizer
:param scheduler_config: dictionary with options for the learning rate
scheduler
:param print_freq: prints short summary every 'print_freq' iterations
:param save_freq: saves checkpoint every 'save_freq' iterations
:param grad_clip: coefficient for gradient clipping
:param batch_first: if True the model uses (batch,seq,feature) tensors,
if false the model uses (seq, batch, feature)
:param save_info: dict with additional state stored in each checkpoint
:param save_path: path to the directiory for checkpoints
:param train_iterations: total number of training iterations to execute
:param checkpoint_filename: name of files with checkpoints
:param keep_checkpoints: max number of checkpoints to keep
:param math: arithmetic type
:param cuda: if True use cuda, if False train on cpu
:param distributed: if True run distributed training
:param intra_epoch_eval: number of additional eval runs within each
training epoch
:param iter_size: number of iterations between weight updates
:param translator: instance of Translator, runs inference on test set
:param verbose: enables verbose logging
"""
super(Seq2SeqTrainer, self).__init__()
self.model = model
self.criterion = criterion
self.epoch = 0
self.save_info = save_info
self.save_path = save_path
self.save_freq = save_freq
self.save_counter = 0
self.checkpoint_filename = checkpoint_filename
self.checkpoint_counter = cycle(range(keep_checkpoints))
self.opt_config = opt_config
self.cuda = cuda
self.distributed = distributed
self.print_freq = print_freq
self.batch_first = batch_first
self.verbose = verbose
self.loss = None
self.translator = translator
self.intra_epoch_eval = intra_epoch_eval
self.iter_size = iter_size
if cuda:
self.model = self.model.cuda()
self.criterion = self.criterion.cuda()
if math == 'fp16':
self.model = self.model.half()
if distributed:
self.model = DDP(self.model)
if math == 'fp16':
self.fp_optimizer = Fp16Optimizer(self.model, grad_clip)
params = self.fp_optimizer.fp32_params
elif math == 'fp32':
self.fp_optimizer = Fp32Optimizer(self.model, grad_clip)
params = self.model.parameters()
opt_name = opt_config.pop('optimizer')
self.optimizer = torch.optim.__dict__[opt_name](params, **opt_config)
logging.info(f'Using optimizer: {self.optimizer}')
self.scheduler = WarmupMultiStepLR(self.optimizer, train_iterations,
**scheduler_config)
def iterate(self, src, tgt, update=True, training=True):
"""
Performs one iteration of the training/validation.
:param src: batch of examples from the source language
:param tgt: batch of examples from the target language
:param update: if True: optimizer does update of the weights
:param training: if True: executes optimizer
"""
src, src_length = src
tgt, tgt_length = tgt
src_length = torch.LongTensor(src_length)
tgt_length = torch.LongTensor(tgt_length)
num_toks = {}
num_toks['tgt'] = int(sum(tgt_length - 1))
num_toks['src'] = int(sum(src_length))
if self.cuda:
src = src.cuda()
src_length = src_length.cuda()
tgt = tgt.cuda()
if self.batch_first:
output = self.model(src, src_length, tgt[:, :-1])
tgt_labels = tgt[:, 1:]
T, B = output.size(1), output.size(0)
else:
output = self.model(src, src_length, tgt[:-1])
tgt_labels = tgt[1:]
T, B = output.size(0), output.size(1)
loss = self.criterion(output.view(T * B, -1),
tgt_labels.contiguous().view(-1))
loss_per_batch = loss.item()
loss /= (B * self.iter_size)
if training:
self.fp_optimizer.step(loss, self.optimizer, self.scheduler,
update)
loss_per_token = loss_per_batch / num_toks['tgt']
loss_per_sentence = loss_per_batch / B
return loss_per_token, loss_per_sentence, num_toks
def feed_data(self, data_loader, training=True):
"""
Runs training or validation on batches from data_loader.
:param data_loader: data loader
:param training: if True runs training else runs validation
"""
if training:
assert self.optimizer is not None
eval_fractions = np.linspace(0, 1, self.intra_epoch_eval + 2)[1:-1]
iters_with_update = len(data_loader) // self.iter_size
eval_iters = (eval_fractions * iters_with_update).astype(int)
eval_iters = eval_iters * self.iter_size
eval_iters = set(eval_iters)
batch_time = AverageMeter()
data_time = AverageMeter()
losses_per_token = AverageMeter(skip_first=False)
losses_per_sentence = AverageMeter(skip_first=False)
tot_tok_time = AverageMeter()
src_tok_time = AverageMeter()
tgt_tok_time = AverageMeter()
batch_size = data_loader.batch_size
end = time.time()
for i, (src, tgt) in enumerate(data_loader):
self.save_counter += 1
# measure data loading time
data_time.update(time.time() - end)
update = False
if i % self.iter_size == self.iter_size - 1:
update = True
# do a train/evaluate iteration
stats = self.iterate(src, tgt, update, training=training)
loss_per_token, loss_per_sentence, num_toks = stats
# measure accuracy and record loss
losses_per_token.update(loss_per_token, num_toks['tgt'])
losses_per_sentence.update(loss_per_sentence, batch_size)
# measure elapsed time
elapsed = time.time() - end
batch_time.update(elapsed)
src_tok_time.update(num_toks['src'] / elapsed)
tgt_tok_time.update(num_toks['tgt'] / elapsed)
tot_num_toks = num_toks['tgt'] + num_toks['src']
tot_tok_time.update(tot_num_toks / elapsed)
self.loss = losses_per_token.avg
if training and i in eval_iters:
test_bleu, _ = self.translator.run(calc_bleu=True,
epoch=self.epoch,
iteration=i)
log = []
log += [f'TRAIN [{self.epoch}][{i}/{len(data_loader)}]']
log += [f'BLEU: {test_bleu:.2f}']
log = '\t'.join(log)
logging.info(log)
self.model.train()
self.preallocate(data_loader, training=True)
if i % self.print_freq == 0:
phase = 'TRAIN' if training else 'VALIDATION'
log = []
log += [f'{phase} [{self.epoch}][{i}/{len(data_loader)}]']
log += [f'Time {batch_time.val:.3f} ({batch_time.avg:.3f})']
log += [f'Data {data_time.val:.2e} ({data_time.avg:.2e})']
log += [
f'Tok/s {tot_tok_time.val:.0f} ({tot_tok_time.avg:.0f})'
]
if self.verbose:
log += [
f'Src tok/s {src_tok_time.val:.0f} ({src_tok_time.avg:.0f})'
]
log += [
f'Tgt tok/s {tgt_tok_time.val:.0f} ({tgt_tok_time.avg:.0f})'
]
log += [
f'Loss/sentence {losses_per_sentence.val:.1f} ({losses_per_sentence.avg:.1f})'
]
log += [
f'Loss/tok {losses_per_token.val:.4f} ({losses_per_token.avg:.4f})'
]
if training:
lr = self.optimizer.param_groups[0]['lr']
log += [f'LR {lr:.3e}']
log = '\t'.join(log)
logging.info(log)
save_chkpt = (self.save_counter %
self.save_freq) == (self.save_freq - 1)
if training and save_chkpt:
self.save_counter = 0
self.save_info['iteration'] = i
identifier = next(self.checkpoint_counter, -1)
if identifier != -1:
with sync_workers() as rank:
if rank == 0:
self.save(identifier=identifier)
end = time.time()
tot_tok_time.reduce('sum')
losses_per_token.reduce('mean')
return losses_per_token.avg, tot_tok_time.avg
def preallocate(self, data_loader, training):
"""
Generates maximum sequence length batch and runs forward and backward
pass without updating model parameters.
:param data_loader: data loader
:param training: if True preallocates memory for backward pass
"""
batch_size = data_loader.batch_size
max_len = data_loader.dataset.max_len
src_length = [max_len] * batch_size
tgt_length = [max_len] * batch_size
if self.batch_first:
shape = (batch_size, max_len)
else:
shape = (max_len, batch_size)
src = torch.full(shape, 4, dtype=torch.int64)
tgt = torch.full(shape, 4, dtype=torch.int64)
src = src, src_length
tgt = tgt, tgt_length
self.iterate(src, tgt, update=False, training=training)
self.model.zero_grad()
def optimize(self, data_loader):
"""
Sets model in training mode, preallocates memory and runs training on
data provided by data_loader.
:param data_loader: data loader
"""
torch.set_grad_enabled(True)
self.model.train()
torch.cuda.empty_cache()
self.preallocate(data_loader, training=True)
output = self.feed_data(data_loader, training=True)
self.model.zero_grad()
torch.cuda.empty_cache()
return output
def evaluate(self, data_loader):
"""
Sets model in eval mode, disables gradients, preallocates memory and
runs validation on data provided by data_loader.
:param data_loader: data loader
"""
torch.set_grad_enabled(False)
self.model.eval()
torch.cuda.empty_cache()
self.preallocate(data_loader, training=False)
output = self.feed_data(data_loader, training=False)
self.model.zero_grad()
torch.cuda.empty_cache()
return output
def load(self, filename):
"""
Loads checkpoint from filename.
:param filename: path to the checkpoint file
"""
if os.path.isfile(filename):
checkpoint = torch.load(filename, map_location={'cuda:0': 'cpu'})
if self.distributed:
self.model.module.load_state_dict(checkpoint['state_dict'])
else:
self.model.load_state_dict(checkpoint['state_dict'])
self.fp_optimizer.initialize_model(self.model)
self.optimizer.load_state_dict(checkpoint['optimizer'])
self.scheduler.load_state_dict(checkpoint['scheduler'])
self.epoch = checkpoint['epoch']
self.loss = checkpoint['loss']
logging.info(f'Loaded checkpoint {filename} (epoch {self.epoch})')
else:
logging.error(f'Invalid checkpoint: {filename}')
def save(self, identifier=None, is_best=False, save_all=False):
"""
Stores checkpoint to a file.
:param identifier: identifier for periodic checkpoint
:param is_best: if True stores checkpoint to 'model_best.pth'
:param save_all: if True stores checkpoint after completed training
epoch
"""
def write_checkpoint(state, filename):
filename = os.path.join(self.save_path, filename)
logging.info(f'Saving model to {filename}')
torch.save(state, filename)
if self.distributed:
model_state = self.model.module.state_dict()
else:
model_state = self.model.state_dict()
state = {
'epoch': self.epoch,
'state_dict': model_state,
'optimizer': self.optimizer.state_dict(),
'scheduler': self.scheduler.state_dict(),
'loss': getattr(self, 'loss', None),
}
state = dict(list(state.items()) + list(self.save_info.items()))
if identifier is not None:
filename = self.checkpoint_filename % identifier
write_checkpoint(state, filename)
if is_best:
filename = 'model_best.pth'
write_checkpoint(state, filename)
if save_all:
filename = f'checkpoint_epoch_{self.epoch:03d}.pth'
write_checkpoint(state, filename)
class Seq2SeqTrainer:
"""
Seq2SeqTrainer
"""
def __init__(self,
model,
criterion,
opt_config,
scheduler_config,
print_freq=10,
save_freq=1000,
grad_clip=float('inf'),
batch_first=False,
save_info={},
save_path='.',
checkpoint_filename='checkpoint%s.pth',
keep_checkpoints=5,
math='fp32',
cuda=True,
distributed=False,
distributed_overlap_allreduce=False,
distributed_overlap_allreduce_messagesize=1e7,
intra_epoch_eval=0,
translator=None,
verbose=False,
arch="gnmt"):
super(Seq2SeqTrainer, self).__init__()
self.model = model
self.criterion = criterion
self.epoch = 0
self.save_info = save_info
self.save_path = save_path
self.save_freq = save_freq
self.save_counter = 0
self.checkpoint_filename = checkpoint_filename
self.checkpoint_counter = cycle(range(keep_checkpoints))
self.opt_config = opt_config
self.cuda = cuda
self.distributed = distributed
self.print_freq = print_freq
self.batch_first = batch_first
self.verbose = verbose
self.loss = None
self.translator = translator
self.intra_epoch_eval = intra_epoch_eval
self.arch = arch
self.retain_allreduce_buffers = True
self.gradient_average = False
if cuda:
self.model = self.model.cuda()
self.criterion = self.criterion.cuda()
if math == 'fp16':
self.model = self.model.half()
if distributed:
# self.model = apex.parallel.DistributedDataParallel(self.model, message_size=10000000, delay_allreduce=True)
self.model = apex.parallel.DistributedDataParallel(
self.model,
message_size=distributed_overlap_allreduce_messagesize,
delay_allreduce=(not distributed_overlap_allreduce),
retain_allreduce_buffers=self.retain_allreduce_buffers,
gradient_average=self.gradient_average)
self.fp_optimizer = Fp16Optimizer(self.model, grad_clip)
params = [self.fp_optimizer.fp32_params]
elif math == 'fp32':
if distributed:
# self.model = apex.parallel.DistributedDataParallel(self.model, message_size=10000000, delay_allreduce=True)
self.model = apex.parallel.DistributedDataParallel(
self.model,
message_size=distributed_overlap_allreduce_messagesize,
delay_allreduce=(not distributed_overlap_allreduce))
self.fp_optimizer = Fp32Optimizer(self.model, grad_clip)
params = self.model.parameters()
opt_name = opt_config.pop('optimizer')
if opt_name == 'FusedAdam':
self.optimizer = apex.optimizers.FusedAdam(params, **opt_config)
else:
self.optimizer = torch.optim.__dict__[opt_name](params,
**opt_config)
gnmt_print(key=mlperf_log.OPT_NAME, value=mlperf_log.ADAM)
gnmt_print(key=mlperf_log.OPT_LR, value=opt_config['lr'])
gnmt_print(key=mlperf_log.OPT_HP_ADAM_BETA1,
value=self.optimizer.defaults['betas'][0])
gnmt_print(key=mlperf_log.OPT_HP_ADAM_BETA2,
value=self.optimizer.defaults['betas'][1])
gnmt_print(key=mlperf_log.OPT_HP_ADAM_EPSILON,
value=self.optimizer.defaults['eps'])
self.scheduler = WarmupMultiStepLR(
self.optimizer,
lr_method=scheduler_config["lr_method"],
warmup_iters=scheduler_config["warmup_iters"],
remain_steps=scheduler_config["remain_steps"],
decay_steps=scheduler_config["decay_steps"])
logging.info(f'Using optimizer: {self.optimizer}')
def iterate(self, src, tgt, update=True, training=True):
src, src_length = src
tgt, tgt_length = tgt
src_length = torch.LongTensor(src_length)
tgt_length = torch.LongTensor(tgt_length)
num_toks = {}
num_toks['tgt'] = int(sum(tgt_length - 1))
num_toks['src'] = int(sum(src_length))
if self.cuda:
src = src.cuda()
src_length = src_length.cuda()
tgt = tgt.cuda()
if self.batch_first:
output = self.model(src, src_length, tgt[:, :-1])
tgt_labels = tgt[:, 1:]
T, B = output.size(1), output.size(0)
else:
output = self.model(src, src_length, tgt[:-1])
tgt_labels = tgt[1:]
T, B = output.size(0), output.size(1)
loss = self.criterion(output.view(T * B, -1),
tgt_labels.contiguous().view(-1))
loss_per_batch = loss.item()
loss /= B
if training:
self.fp_optimizer.step(loss, self.optimizer, self.scheduler,
update)
loss_per_token = loss_per_batch / num_toks['tgt']
loss_per_sentence = loss_per_batch / B
return loss_per_token, loss_per_sentence, num_toks
def feed_data(self, data_loader, training=True):
"""
Runs training or validation on batches from data_loader.
:param data_loader: data loader
:param training: if True runs training else runs validation
"""
if training:
assert self.optimizer is not None
eval_fractions = np.linspace(0, 1, self.intra_epoch_eval + 2)[1:-1]
eval_iters = (eval_fractions * len(data_loader)).astype(int)
eval_iters = set(eval_iters)
batch_time = AverageMeter()
data_time = AverageMeter()
losses_per_token = AverageMeter()
losses_per_sentence = AverageMeter()
tot_tok_time = AverageMeter()
src_tok_time = AverageMeter()
tgt_tok_time = AverageMeter()
batch_size = data_loader.batch_size
layer_timestamps = []
verbose = True
module_whitelist = ["EmuBidirLSTM", "RecurrentAttention", "Classifier"]
for i, (src, tgt) in enumerate(data_loader):
break
(src, src_length) = src
(tgt, tgt_length) = tgt
src_length = torch.LongTensor(src_length).cuda()
src = src.cuda()
tgt = tgt.cuda()
model_input = (src, src_length, tgt[:-1])
summary = torchsummary.summary(model=self.model,
module_whitelist=module_whitelist,
model_input=model_input,
verbose=True)
end = time.time()
NUM_STEPS_TO_PROFILE = 100 # profile 100 steps
for i, (src, tgt) in enumerate(data_loader):
self.save_counter += 1
# measure data loading time
data_time.update(time.time() - end)
with torchprofiler.Profiling(self.model, module_whitelist) as p:
# do a train/evaluate iteration
stats = self.iterate(src, tgt, training=training)
loss_per_token, loss_per_sentence, num_toks = stats
print(str(p))
layer_timestamps.append(p.processed_times())
# measure accuracy and record loss
losses_per_token.update(loss_per_token, num_toks['tgt'])
losses_per_sentence.update(loss_per_sentence, batch_size)
# measure elapsed time
elapsed = time.time() - end
batch_time.update(elapsed)
src_tok_time.update(num_toks['src'] / elapsed)
tgt_tok_time.update(num_toks['tgt'] / elapsed)
tot_num_toks = num_toks['tgt'] + num_toks['src']
tot_tok_time.update(tot_num_toks / elapsed)
self.loss = losses_per_token.avg
if training and i in eval_iters:
test_bleu, _ = self.translator.run(calc_bleu=True,
epoch=self.epoch,
iteration=i)
log = []
log += [f'TRAIN [{self.epoch}][{i}/{len(data_loader)}]']
log += [f'BLEU: {test_bleu:.2f}']
log = '\t'.join(log)
logging.info(log)
self.model.train()
self.preallocate(data_loader, training=True)
if i % self.print_freq == 0:
phase = 'TRAIN' if training else 'VALIDATION'
log = []
log += [f'{phase} [{self.epoch}][{i}/{len(data_loader)}]']
log += [f'Time {batch_time.val:.3f} ({batch_time.avg:.3f})']
log += [f'Data {data_time.val:.5f} ({data_time.avg:.5f})']
log += [
f'Tok/s {tot_tok_time.val:.0f} ({tot_tok_time.avg:.0f})'
]
if self.verbose:
log += [
f'Src tok/s {src_tok_time.val:.0f} ({src_tok_time.avg:.0f})'
]
log += [
f'Tgt tok/s {tgt_tok_time.val:.0f} ({tgt_tok_time.avg:.0f})'
]
log += [
f'Loss/sentence {losses_per_sentence.val:.1f} ({losses_per_sentence.avg:.1f})'
]
log += [
f'Loss/tok {losses_per_token.val:.4f} ({losses_per_token.avg:.4f})'
]
lr = [
param_group['lr']
for param_group in self.optimizer.param_groups
]
log += [f'Learning Rate {lr}']
log = '\t'.join(log)
logging.info(log)
if i >= NUM_STEPS_TO_PROFILE:
break
save_chkpt = (self.save_counter %
self.save_freq) == (self.save_freq - 1)
if training and save_chkpt:
self.save_counter = 0
self.save_info['iteration'] = i
identifier = next(self.checkpoint_counter, -1)
if identifier != -1:
with sync_workers() as rank:
if rank == 0:
self.save(identifier=identifier)
end = time.time()
if verbose:
print(
"\n==========================================================")
print("Layer Type Forward Time (ms) Backward Time (ms)")
print("==========================================================")
tot_accounted_time = 0.0
per_layer_times = []
for i in range(len(layer_timestamps[0])):
layer_type = str(layer_timestamps[0][i][0])
layer_forward_time_sum = 0.0
layer_backward_time_sum = 0.0
for j in range(len(layer_timestamps)):
layer_forward_time_sum += (layer_timestamps[j][i][2] / 1000)
layer_backward_time_sum += (layer_timestamps[j][i][5] / 1000)
per_layer_times.append(
(layer_type, layer_forward_time_sum / len(layer_timestamps),
layer_backward_time_sum / len(layer_timestamps)))
if verbose:
print(per_layer_times[-1][0], per_layer_times[-1][1],
per_layer_times[-1][2])
tot_accounted_time += (per_layer_times[-1][1] +
per_layer_times[-1][2])
print("Total accounted time: %.3f ms" % tot_accounted_time)
summary_i = 0
per_layer_times_i = 0
last_summary_i = -1
last_per_layer_times_i = -1
while len(per_layer_times) > 0:
per_layer_time = per_layer_times.pop(0)
for summary_i in range(len(summary)):
summary_elem = summary[summary_i]
if str(summary_elem['layer_name']) != str(per_layer_time[0]):
continue
if 'forward_time' in summary_elem and 'backward_time' in summary_elem:
continue
summary_elem['forward_time'] = per_layer_time[1]
summary_elem['backward_time'] = per_layer_time[2]
break
if training:
create_graph(self.model, module_whitelist, (src, tgt), summary,
os.path.join("profiles", self.arch))
tot_tok_time.reduce('sum')
losses_per_token.reduce('mean')
return losses_per_token.avg, tot_tok_time.avg
def preallocate(self, data_loader, training):
"""
Generates maximum sequence length batch and runs forward and backward
pass without updating model parameters.
:param data_loader: data loader
:param training: if True preallocates memory for backward pass
"""
batch_size = data_loader.batch_size
max_len = data_loader.dataset.max_len
src_length = [max_len] * batch_size
tgt_length = [max_len] * batch_size
if self.batch_first:
shape = (batch_size, max_len)
else:
shape = (max_len, batch_size)
src = torch.full(shape, 4, dtype=torch.int64)
tgt = torch.full(shape, 4, dtype=torch.int64)
src = src, src_length
tgt = tgt, tgt_length
self.iterate(src, tgt, update=False, training=training)
def optimize(self, data_loader):
"""
Sets model in training mode, preallocates memory and runs training on
data provided by data_loader.
:param data_loader: data loader
"""
torch.set_grad_enabled(True)
self.model.train()
torch.cuda.empty_cache()
self.preallocate(data_loader, training=True)
output = self.feed_data(data_loader, training=True)
torch.cuda.empty_cache()
return output
def evaluate(self, data_loader):
"""
Sets model in eval mode, disables gradients, preallocates memory and
runs validation on data provided by data_loader.
:param data_loader: data loader
"""
torch.set_grad_enabled(False)
self.model.eval()
torch.cuda.empty_cache()
self.preallocate(data_loader, training=False)
output = self.feed_data(data_loader, training=False)
torch.cuda.empty_cache()
return output
def load(self, filename):
"""
Loads checkpoint from filename.
:param filename: path to the checkpoint file
"""
if os.path.isfile(filename):
checkpoint = torch.load(filename, map_location={'cuda:0': 'cpu'})
self.model.load_state_dict(checkpoint['state_dict'])
self.fp_optimizer.initialize_model(self.model)
self.optimizer.load_state_dict(checkpoint['optimizer'])
self.scheduler.load_state_dict(checkpoint['scheduler'])
self.epoch = checkpoint['epoch']
self.loss = checkpoint['loss']
logging.info(f'Loaded checkpoint {filename} (epoch {self.epoch})')
else:
logging.error(f'Invalid checkpoint: {filename}')
def save(self, identifier=None, is_best=False, save_all=False):
"""
Stores checkpoint to a file.
:param identifier: identifier for periodic checkpoint
:param is_best: if True stores checkpoint to 'model_best.pth'
:param save_all: if True stores checkpoint after completed training
epoch
"""
def write_checkpoint(state, filename):
filename = os.path.join(self.save_path, filename)
logging.info(f'Saving model to {filename}')
torch.save(state, filename)
state = {
'epoch': self.epoch,
'state_dict': self.model.state_dict(),
'optimizer': self.optimizer.state_dict(),
'scheduler': self.scheduler.state_dict(),
'loss': getattr(self, 'loss', None),
}
state = dict(list(state.items()) + list(self.save_info.items()))
if identifier is not None:
filename = self.checkpoint_filename % identifier
write_checkpoint(state, filename)
if is_best:
filename = 'model_best.pth'
write_checkpoint(state, filename)
if save_all:
filename = f'checkpoint_epoch_{self.epoch:03d}.pth'
write_checkpoint(state, filename)
