338 lines
18 KiB
Python
338 lines
18 KiB
Python
from torch.cuda.amp import GradScaler
|
|
from torch.distributed.optim import ZeroRedundancyOptimizer
|
|
|
|
from utils.loss_accumulator import LossAccumulator
|
|
from torch.nn import Module
|
|
import logging
|
|
from trainer.losses import create_loss
|
|
import torch
|
|
from collections import OrderedDict
|
|
from trainer.inject import create_injector
|
|
from utils.util import recursively_detach, opt_get, clip_grad_norm
|
|
|
|
logger = logging.getLogger('base')
|
|
|
|
|
|
# Defines the expected API for a single training step
|
|
class ConfigurableStep(Module):
|
|
|
|
def __init__(self, opt_step, env):
|
|
super(ConfigurableStep, self).__init__()
|
|
|
|
self.step_opt = opt_step
|
|
self.env = env
|
|
self.opt = env['opt']
|
|
self.gen_outputs = opt_step['generator_outputs']
|
|
self.loss_accumulator = LossAccumulator(buffer_sz=opt_get(opt_step, ['loss_log_buffer'], 50))
|
|
self.optimizers = None
|
|
self.scaler = GradScaler(enabled=self.opt['fp16'] or opt_get(self.opt, ['grad_scaler_enabled'], False))
|
|
self.grads_generated = False
|
|
self.min_total_loss = opt_step['min_total_loss'] if 'min_total_loss' in opt_step.keys() else -999999999
|
|
self.clip_grad_eps = opt_get(opt_step, ['clip_grad_eps'], None)
|
|
|
|
# This is a half-measure that can be used between anomaly_detection and running a potentially problematic
|
|
# trainer bare. With this turned on, the optimizer will not step() if a nan grad is detected. If a model trips
|
|
# this warning 10 times in a row, the training session is aborted and the model state is saved. This has a
|
|
# noticeable affect on training speed, but nowhere near as bad as anomaly_detection.
|
|
self.check_grads_for_nan = opt_get(opt_step, ['check_grads_for_nan'], False)
|
|
self.nan_counter = 0
|
|
|
|
self.injectors = []
|
|
if 'injectors' in self.step_opt.keys():
|
|
injector_names = []
|
|
for inj_name, injector in self.step_opt['injectors'].items():
|
|
assert inj_name not in injector_names # Repeated names are always an error case.
|
|
injector_names.append(inj_name)
|
|
self.injectors.append(create_injector(injector, env))
|
|
|
|
losses = []
|
|
self.weights = {}
|
|
if 'losses' in self.step_opt.keys():
|
|
for loss_name, loss in self.step_opt['losses'].items():
|
|
assert loss_name not in self.weights.keys() # Repeated names are always an error case.
|
|
losses.append((loss_name, create_loss(loss, env)))
|
|
self.weights[loss_name] = loss['weight']
|
|
self.losses = OrderedDict(losses)
|
|
|
|
def get_network_for_name(self, name):
|
|
return self.env['generators'][name] if name in self.env['generators'].keys() \
|
|
else self.env['discriminators'][name]
|
|
|
|
# Subclasses should override this to define individual optimizers. They should all go into self.optimizers.
|
|
# This default implementation defines a single optimizer for all Generator parameters.
|
|
# Must be called after networks are initialized and wrapped.
|
|
def define_optimizers(self):
|
|
opt_configs = [opt_get(self.step_opt, ['optimizer_params'], None)]
|
|
self.optimizers = []
|
|
if opt_configs[0] is None:
|
|
return
|
|
training = self.step_opt['training']
|
|
training_net = self.get_network_for_name(training)
|
|
nets = [training_net]
|
|
training = [training]
|
|
for net_name, net, opt_config in zip(training, nets, opt_configs):
|
|
# Configs can organize parameters by-group and specify different learning rates for each group. This only
|
|
# works in the model specifically annotates which parameters belong in which group using PARAM_GROUP.
|
|
optim_params = {'default': {'params': [], 'lr': opt_config['lr']}}
|
|
if opt_config is not None and 'param_groups' in opt_config.keys():
|
|
for k, pg in opt_config['param_groups'].items():
|
|
optim_params[k] = {'params': [], 'lr': pg['lr']}
|
|
|
|
import torch.nn as nn
|
|
norm_modules = (nn.BatchNorm2d, nn.InstanceNorm2d, nn.BatchNorm1d, nn.InstanceNorm1d,
|
|
nn.BatchNorm3d, nn.InstanceNorm3d, nn.GroupNorm, nn.LayerNorm)
|
|
emb_modules = (nn.Embedding, nn.EmbeddingBag)
|
|
param_names_notweights = set()
|
|
all_param_names = set()
|
|
param_map = {}
|
|
for mn, m in net.named_modules():
|
|
for k, v in m.named_parameters():
|
|
v.is_bias = k.endswith(".bias")
|
|
v.is_weight = k.endswith(".weight")
|
|
v.is_norm = isinstance(m, norm_modules)
|
|
v.is_emb = isinstance(m, emb_modules)
|
|
|
|
fpn = '%s.%s' % (mn, k) if mn else k # full param name
|
|
all_param_names.add(fpn)
|
|
param_map[fpn] = v
|
|
if v.is_bias or v.is_norm or v.is_emb:
|
|
param_names_notweights.add(fpn)
|
|
|
|
# Some models can specify some parameters to be in different groups.
|
|
param_group = "default"
|
|
if hasattr(v, 'PARAM_GROUP'):
|
|
if v.PARAM_GROUP in optim_params.keys():
|
|
param_group = v.PARAM_GROUP
|
|
else:
|
|
logger.warning(f'Model specifies a custom param group {v.PARAM_GROUP} which is not configured. '
|
|
f'The same LR will be used for all parameters.')
|
|
|
|
if v.requires_grad:
|
|
optim_params[param_group]['params'].append(v)
|
|
else:
|
|
if self.env['rank'] <= 0:
|
|
logger.warning('Params [{:s}] will not optimize.'.format(k))
|
|
params_names_notweights = sorted(list(param_names_notweights))
|
|
params_notweights = [param_map[k] for k in params_names_notweights]
|
|
params_names_weights = sorted(list(all_param_names ^ param_names_notweights))
|
|
params_weights = [param_map[k] for k in params_names_weights]
|
|
|
|
if 'optimizer' not in self.step_opt.keys() or self.step_opt['optimizer'] == 'adam':
|
|
opt = torch.optim.Adam(list(optim_params.values()), lr=opt_config['lr'],
|
|
weight_decay=opt_config['weight_decay'],
|
|
betas=(opt_config['beta1'], opt_config['beta2']))
|
|
opt._group_names = sorted(list(all_param_names))
|
|
elif self.step_opt['optimizer'] == 'adamw':
|
|
groups = [
|
|
{ 'params': params_weights, 'weight_decay': opt_get(opt_config, ['weight_decay'], 0) },
|
|
{ 'params': params_notweights, 'weight_decay': 0 }
|
|
]
|
|
opt = torch.optim.AdamW(groups, lr=opt_config['lr'],
|
|
weight_decay=opt_get(opt_config, ['weight_decay'], 1e-2),
|
|
betas=(opt_get(opt_config, ['beta1'], .9), opt_get(opt_config, ['beta2'], .999)))
|
|
opt._group_names = [params_names_weights, params_names_notweights]
|
|
elif self.step_opt['optimizer'] == 'adamw_zero':
|
|
# The torch ZeRO implementation does not seem to support parameter groups, so do not shard the non-weighted
|
|
# parameters and just use a normal AdamW implementation. In a large network, these weights will normally
|
|
# be a tiny fraction of the total weights.
|
|
opt_unweighted = torch.optim.AdamW(params_notweights, lr=opt_config['lr'], weight_decay=0,
|
|
betas=(opt_get(opt_config, ['beta1'], .9), opt_get(opt_config, ['beta2'], .999)))
|
|
opt_unweighted._config = opt_config
|
|
opt_unweighted._config['network'] = net_name
|
|
self.optimizers.append(opt_unweighted)
|
|
# Not setting these means abnormal gradient detection below no longer works.
|
|
opt_unweighted._group_names = []
|
|
opt = ZeroRedundancyOptimizer(params_weights, optimizer_class=torch.optim.AdamW, lr=opt_config['lr'],
|
|
weight_decay=opt_get(opt_config, ['weight_decay'], 1e-2),
|
|
betas=(opt_get(opt_config, ['beta1'], .9), opt_get(opt_config, ['beta2'], .999)))
|
|
opt.param_groups[0]['initial_lr'] = opt_config['lr']
|
|
opt._group_names = []
|
|
elif self.step_opt['optimizer'] == 'lars':
|
|
from trainer.optimizers.larc import LARC
|
|
from trainer.optimizers.sgd import SGDNoBiasMomentum
|
|
optSGD = SGDNoBiasMomentum(list(optim_params.values()), lr=opt_config['lr'], momentum=opt_config['momentum'],
|
|
weight_decay=opt_config['weight_decay'])
|
|
opt = LARC(optSGD, trust_coefficient=opt_config['lars_coefficient'])
|
|
opt._group_names = sorted(list(all_param_names))
|
|
elif self.step_opt['optimizer'] == 'sgd':
|
|
from torch.optim import SGD
|
|
opt = SGD(list(optim_params.values()), lr=opt_config['lr'], momentum=opt_config['momentum'], weight_decay=opt_config['weight_decay'])
|
|
opt._group_names = sorted(list(all_param_names))
|
|
opt._config = opt_config # This is a bit seedy, but we will need these configs later.
|
|
opt._config['network'] = net_name
|
|
self.optimizers.append(opt)
|
|
|
|
# Returns all optimizers used in this step.
|
|
def get_optimizers(self):
|
|
assert self.optimizers is not None
|
|
return self.optimizers
|
|
|
|
# Returns optimizers which are opting in for default LR scheduling.
|
|
def get_optimizers_with_default_scheduler(self):
|
|
assert self.optimizers is not None
|
|
return self.optimizers
|
|
|
|
# Returns the names of the networks this step will train. Other networks will be frozen.
|
|
def get_networks_trained(self):
|
|
if isinstance(self.step_opt['training'], list):
|
|
return self.step_opt['training']
|
|
else:
|
|
return [self.step_opt['training']]
|
|
|
|
def get_training_network_name(self):
|
|
if isinstance(self.step_opt['training'], list):
|
|
return self.step_opt['training'][0]
|
|
else:
|
|
return self.step_opt['training']
|
|
|
|
# Performs all forward and backward passes for this step given an input state. All input states are lists of
|
|
# chunked tensors. Use grad_accum_step to dereference these steps. Should return a dict of tensors that later
|
|
# steps might use. These tensors are automatically detached and accumulated into chunks.
|
|
def do_forward_backward(self, state, grad_accum_step, amp_loss_id, train=True, no_ddp_sync=False, loss_accumulator=None):
|
|
local_state = {} # <-- Will store the entire local state to be passed to injectors & losses.
|
|
new_state = {} # <-- Will store state values created by this step for returning to ExtensibleTrainer.
|
|
for k, v in state.items():
|
|
local_state[k] = v[grad_accum_step]
|
|
local_state['train_nets'] = str(self.get_networks_trained())
|
|
loss_accumulator = self.loss_accumulator if loss_accumulator is None else loss_accumulator
|
|
|
|
# Some losses compute backward() internally. Accommodate this by stashing the amp_loss_id in env.
|
|
self.env['amp_loss_id'] = amp_loss_id
|
|
self.env['current_step_optimizers'] = self.optimizers
|
|
self.env['training'] = train
|
|
|
|
# Inject in any extra dependencies.
|
|
for inj in self.injectors:
|
|
# Don't do injections tagged with eval unless we are not in train mode.
|
|
if train and 'eval' in inj.opt.keys() and inj.opt['eval']:
|
|
continue
|
|
# Likewise, don't do injections tagged with train unless we are not in eval.
|
|
if not train and 'train' in inj.opt.keys() and inj.opt['train']:
|
|
continue
|
|
# Don't do injections tagged with 'after' or 'before' when we are out of spec.
|
|
if 'after' in inj.opt.keys() and self.env['step'] < inj.opt['after'] or \
|
|
'before' in inj.opt.keys() and self.env['step'] > inj.opt['before'] or \
|
|
'every' in inj.opt.keys() and self.env['step'] % inj.opt['every'] != 0:
|
|
continue
|
|
if 'no_accum' in inj.opt.keys() and grad_accum_step > 0:
|
|
continue
|
|
training_net = self.get_network_for_name(self.step_opt['training'])
|
|
if no_ddp_sync and hasattr(training_net, 'no_sync'):
|
|
with training_net.no_sync():
|
|
injected = inj(local_state)
|
|
elif opt_get(inj.opt, ['no_grad'], False):
|
|
with torch.no_grad():
|
|
injected = inj(local_state)
|
|
else:
|
|
injected = inj(local_state)
|
|
local_state.update(injected)
|
|
new_state.update(injected)
|
|
|
|
if len(self.losses) > 0:
|
|
# Finally, compute the losses.
|
|
total_loss = 0
|
|
for loss_name, loss in self.losses.items():
|
|
# Some losses only activate after a set number of steps. For example, proto-discriminator losses can
|
|
# be very disruptive to a generator.
|
|
if 'after' in loss.opt.keys() and loss.opt['after'] > self.env['step'] or \
|
|
'before' in loss.opt.keys() and self.env['step'] > loss.opt['before'] or \
|
|
'every' in loss.opt.keys() and self.env['step'] % loss.opt['every'] != 0:
|
|
continue
|
|
if loss.is_stateful():
|
|
l, lstate = loss(self.get_network_for_name(self.step_opt['training']), local_state)
|
|
local_state.update(lstate)
|
|
new_state.update(lstate)
|
|
else:
|
|
l = loss(self.get_network_for_name(self.step_opt['training']), local_state)
|
|
if not l.isfinite():
|
|
print(f'!!Detected non-finite loss {loss_name}')
|
|
total_loss += l * self.weights[loss_name]
|
|
# Record metrics.
|
|
if isinstance(l, torch.Tensor):
|
|
loss_accumulator.add_loss(loss_name, l)
|
|
for n, v in loss.extra_metrics():
|
|
loss_accumulator.add_loss("%s_%s" % (loss_name, n), v)
|
|
loss.clear_metrics()
|
|
|
|
# In some cases, the loss could not be set (e.g. all losses have 'after')
|
|
if train and isinstance(total_loss, torch.Tensor):
|
|
loss_accumulator.add_loss("%s_total" % (self.get_training_network_name(),), total_loss)
|
|
reset_required = total_loss < self.min_total_loss
|
|
|
|
# Scale the loss down by the accumulation factor.
|
|
total_loss = total_loss / self.env['mega_batch_factor']
|
|
|
|
# Get dem grads!
|
|
self.scaler.scale(total_loss).backward()
|
|
|
|
if reset_required:
|
|
# You might be scratching your head at this. Why would you zero grad as opposed to not doing a
|
|
# backwards? Because DDP uses the backward() pass as a synchronization point and there is not a good
|
|
# way to simply bypass backward. If you want a more efficient way to specify a min_loss, use or
|
|
# implement it at the loss level.
|
|
self.get_network_for_name(self.step_opt['training']).zero_grad()
|
|
loss_accumulator.increment_metric("%s_skipped_steps" % (self.get_training_network_name(),))
|
|
|
|
self.grads_generated = True
|
|
|
|
# Detach all state variables. Within the step, gradients can flow. Once these variables leave the step
|
|
# we must release the gradients.
|
|
new_state = recursively_detach(new_state)
|
|
|
|
# Prune state outputs that are not actually needed.
|
|
if 'step_outputs' in self.step_opt.keys():
|
|
nst = {}
|
|
for k in self.step_opt['step_outputs']:
|
|
nst[k] = new_state[k]
|
|
new_state = nst
|
|
|
|
return new_state
|
|
|
|
# Performs the optimizer step after all gradient accumulation is completed. Default implementation simply steps()
|
|
# all self.optimizers.
|
|
def do_step(self, step):
|
|
if not self.grads_generated:
|
|
return
|
|
self.grads_generated = False
|
|
for opt in self.optimizers:
|
|
# Optimizers can be opted out in the early stages of training.
|
|
after = opt._config['after'] if 'after' in opt._config.keys() else 0
|
|
after_network = self.opt['networks'][opt._config['network']]['after'] if 'after' in self.opt['networks'][opt._config['network']].keys() else 0
|
|
after = max(after, after_network)
|
|
if self.env['step'] < after:
|
|
continue
|
|
before = opt._config['before'] if 'before' in opt._config.keys() else -1
|
|
if before != -1 and self.env['step'] > before:
|
|
continue
|
|
|
|
nan_found = False
|
|
if self.check_grads_for_nan:
|
|
for pg in opt.param_groups:
|
|
for p in pg['params']:
|
|
if not torch.isfinite(p.grad).any():
|
|
nan_found = True
|
|
break
|
|
if nan_found:
|
|
break
|
|
if nan_found:
|
|
print("NaN found in grads. Throwing this step out.")
|
|
self.nan_counter += 1
|
|
else:
|
|
self.nan_counter = 0
|
|
|
|
if self.clip_grad_eps is not None and self.clip_grad_eps != 0:
|
|
for pgn, pg in zip(opt._group_names, opt.param_groups):
|
|
grad_norm = clip_grad_norm(pg['params'], pgn, self.clip_grad_eps)
|
|
if torch.isnan(grad_norm):
|
|
nan_found = True
|
|
self.nan_counter += 1
|
|
|
|
if not nan_found:
|
|
self.scaler.step(opt)
|
|
self.scaler.update()
|
|
else:
|
|
opt.zero_grad()
|
|
|
|
def get_metrics(self):
|
|
return self.loss_accumulator.as_dict()
|