mmselfsup/openselfsup/apis/train.py

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2020-06-16 00:05:18 +08:00
import random
import re
from collections import OrderedDict
import numpy as np
import torch
import torch.distributed as dist
from mmcv.parallel import MMDataParallel, MMDistributedDataParallel
from mmcv.runner import DistSamplerSeedHook, Runner, obj_from_dict
from openselfsup.datasets import build_dataloader
from openselfsup.hooks import build_hook, DistOptimizerHook
from openselfsup.utils import get_root_logger, optimizers, print_log
def set_random_seed(seed, deterministic=False):
"""Set random seed.
Args:
seed (int): Seed to be used.
deterministic (bool): Whether to set the deterministic option for
CUDNN backend, i.e., set `torch.backends.cudnn.deterministic`
to True and `torch.backends.cudnn.benchmark` to False.
Default: False.
"""
random.seed(seed)
np.random.seed(seed)
torch.manual_seed(seed)
torch.cuda.manual_seed_all(seed)
if deterministic:
torch.backends.cudnn.deterministic = True
torch.backends.cudnn.benchmark = False
def parse_losses(losses):
log_vars = OrderedDict()
for loss_name, loss_value in losses.items():
if isinstance(loss_value, torch.Tensor):
log_vars[loss_name] = loss_value.mean()
elif isinstance(loss_value, list):
log_vars[loss_name] = sum(_loss.mean() for _loss in loss_value)
else:
raise TypeError(
'{} is not a tensor or list of tensors'.format(loss_name))
loss = sum(_value for _key, _value in log_vars.items() if 'loss' in _key)
log_vars['loss'] = loss
for loss_name, loss_value in log_vars.items():
# reduce loss when distributed training
if dist.is_available() and dist.is_initialized():
loss_value = loss_value.data.clone()
dist.all_reduce(loss_value.div_(dist.get_world_size()))
log_vars[loss_name] = loss_value.item()
return loss, log_vars
def batch_processor(model, data, train_mode):
"""Process a data batch.
This method is required as an argument of Runner, which defines how to
process a data batch and obtain proper outputs. The first 3 arguments of
batch_processor are fixed.
Args:
model (nn.Module): A PyTorch model.
data (dict): The data batch in a dict.
train_mode (bool): Training mode or not. It may be useless for some
models.
Returns:
dict: A dict containing losses and log vars.
"""
assert model.training, "Must be in training mode."
losses = model(**data)
loss, log_vars = parse_losses(losses)
outputs = dict(
loss=loss, log_vars=log_vars, num_samples=len(data['img'].data))
return outputs
def train_model(model,
dataset,
cfg,
distributed=False,
timestamp=None,
meta=None):
logger = get_root_logger(cfg.log_level)
# start training
if distributed:
_dist_train(
model, dataset, cfg, logger=logger, timestamp=timestamp, meta=meta)
else:
_non_dist_train(
model, dataset, cfg, logger=logger, timestamp=timestamp, meta=meta)
def build_optimizer(model, optimizer_cfg):
"""Build optimizer from configs.
Args:
model (:obj:`nn.Module`): The model with parameters to be optimized.
optimizer_cfg (dict): The config dict of the optimizer.
Positional fields are:
- type: class name of the optimizer.
- lr: base learning rate.
Optional fields are:
- any arguments of the corresponding optimizer type, e.g.,
weight_decay, momentum, etc.
- paramwise_options: a dict with regular expression as keys
to match parameter names and a dict containing options as
values. Options include 6 fields: lr, lr_mult, momentum,
momentum_mult, weight_decay, weight_decay_mult.
Returns:
torch.optim.Optimizer: The initialized optimizer.
Example:
>>> model = torch.nn.modules.Conv1d(1, 1, 1)
>>> paramwise_options = {
>>> '(bn|gn)(\d+)?.(weight|bias)': dict(weight_decay_mult=0.1),
>>> '\Ahead.': dict(lr_mult=10, momentum=0)}
>>> optimizer_cfg = dict(type='SGD', lr=0.01, momentum=0.9,
>>> weight_decay=0.0001,
>>> paramwise_options=paramwise_options)
>>> optimizer = build_optimizer(model, optimizer_cfg)
"""
if hasattr(model, 'module'):
model = model.module
optimizer_cfg = optimizer_cfg.copy()
paramwise_options = optimizer_cfg.pop('paramwise_options', None)
# if no paramwise option is specified, just use the global setting
if paramwise_options is None:
return obj_from_dict(optimizer_cfg, optimizers,
dict(params=model.parameters()))
else:
assert isinstance(paramwise_options, dict)
params = []
for name, param in model.named_parameters():
param_group = {'params': [param]}
if not param.requires_grad:
params.append(param_group)
continue
for regexp, options in paramwise_options.items():
if re.search(regexp, name):
for key, value in options.items():
if key.endswith('_mult'): # is a multiplier
key = key[:-5]
assert key in optimizer_cfg, \
"{} not in optimizer_cfg".format(key)
value = optimizer_cfg[key] * value
param_group[key] = value
if not dist.is_initialized() or dist.get_rank() == 0:
print_log('paramwise_options -- {}: {}={}'.format(
name, key, value))
# otherwise use the global settings
params.append(param_group)
optimizer_cls = getattr(optimizers, optimizer_cfg.pop('type'))
return optimizer_cls(params, **optimizer_cfg)
def _dist_train(model, dataset, cfg, logger=None, timestamp=None, meta=None):
# prepare data loaders
dataset = dataset if isinstance(dataset, (list, tuple)) else [dataset]
data_loaders = [
build_dataloader(
ds,
cfg.data.imgs_per_gpu,
cfg.data.workers_per_gpu,
dist=True,
shuffle=True,
replace=getattr(cfg.data, 'sampling_replace', False),
seed=cfg.seed,
drop_last=getattr(cfg.data, 'drop_last', False)) for ds in dataset
]
# put model on gpus
model = MMDistributedDataParallel(
model.cuda(),
device_ids=[torch.cuda.current_device()],
broadcast_buffers=False)
# build runner
optimizer = build_optimizer(model, cfg.optimizer)
runner = Runner(
model,
batch_processor,
optimizer,
cfg.work_dir,
logger=logger,
meta=meta)
# an ugly walkaround to make the .log and .log.json filenames the same
runner.timestamp = timestamp
optimizer_config = DistOptimizerHook(**cfg.optimizer_config)
# register hooks
runner.register_training_hooks(cfg.lr_config, optimizer_config,
cfg.checkpoint_config, cfg.log_config)
runner.register_hook(DistSamplerSeedHook())
# register custom hooks
for hook in cfg.get('custom_hooks', ()):
if hook.type == 'DeepClusterHook':
common_params = dict(dist_mode=True, data_loaders=data_loaders)
else:
common_params = dict(dist_mode=True)
runner.register_hook(build_hook(hook, common_params))
if cfg.resume_from:
runner.resume(cfg.resume_from)
elif cfg.load_from:
runner.load_checkpoint(cfg.load_from)
runner.run(data_loaders, cfg.workflow, cfg.total_epochs)
def _non_dist_train(model,
dataset,
cfg,
validate=False,
logger=None,
timestamp=None,
meta=None):
# prepare data loaders
dataset = dataset if isinstance(dataset, (list, tuple)) else [dataset]
data_loaders = [
build_dataloader(
ds,
cfg.data.imgs_per_gpu,
cfg.data.workers_per_gpu,
cfg.gpus,
dist=False,
shuffle=True,
replace=getattr(cfg.data, 'sampling_replace', False),
seed=cfg.seed,
drop_last=getattr(cfg.data, 'drop_last', False)) for ds in dataset
]
# put model on gpus
model = MMDataParallel(model, device_ids=range(cfg.gpus)).cuda()
# build runner
optimizer = build_optimizer(model, cfg.optimizer)
runner = Runner(
model,
batch_processor,
optimizer,
cfg.work_dir,
logger=logger,
meta=meta)
# an ugly walkaround to make the .log and .log.json filenames the same
runner.timestamp = timestamp
optimizer_config = cfg.optimizer_config
runner.register_training_hooks(cfg.lr_config, optimizer_config,
cfg.checkpoint_config, cfg.log_config)
# register custom hooks
for hook in cfg.get('custom_hooks', ()):
if hook.type == 'DeepClusterHook':
common_params = dict(dist_mode=False, data_loaders=data_loaders)
else:
common_params = dict(dist_mode=False)
runner.register_hook(build_hook(hook, common_params))
if cfg.resume_from:
runner.resume(cfg.resume_from)
elif cfg.load_from:
runner.load_checkpoint(cfg.load_from)
runner.run(data_loaders, cfg.workflow, cfg.total_epochs)