add exemplary training data. update to nvidia apex. refactor 'item -> line in doc' mapping. add warning for unknown word.

This commit is contained in:
tholor 2018-12-20 18:30:52 +01:00
parent 17595ef2de
commit e5fc98c542
2 changed files with 71 additions and 95 deletions

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@ -498,8 +498,8 @@ loss = 0.06423990014260186
#### LM Fine-tuning
The data should be a text file in the same format as [sample_text.txt](./samples/sample_text.txt) (one sentence per line, docs separated by empty line).
Training one epoch on a 500k sentence corpus takes about 1:20h on 4 x NVIDIA Tesla P100 with `train_batch_size=200` and `max_seq_length=128`:
You can download an [exemplary training corpus](https://ext-bert-sample.obs.eu-de.otc.t-systems.com/small_wiki_sentence_corpus.txt) generated from wikipedia articles and splitted into ~500k sentences with spaCy.
Training one epoch on this corpus takes about 1:20h on 4 x NVIDIA Tesla P100 with `train_batch_size=200` and `max_seq_length=128`:
```shell

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@ -1,5 +1,6 @@
# coding=utf-8
# Copyright 2018 The Google AI Language Team Authors and The HugginFace Inc. team.
# Copyright (c) 2018, NVIDIA CORPORATION. All rights reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
@ -41,6 +42,12 @@ logging.basicConfig(format='%(asctime)s - %(levelname)s - %(name)s - %(message
logger = logging.getLogger(__name__)
def warmup_linear(x, warmup=0.002):
if x < warmup:
return x/warmup
return 1.0 - x
class BERTDataset(Dataset):
def __init__(self, corpus_path, tokenizer, seq_len, encoding="utf-8", corpus_lines=None, on_memory=True):
self.vocab = tokenizer.vocab
@ -59,6 +66,7 @@ class BERTDataset(Dataset):
# for loading samples in memory
self.current_random_doc = 0
self.num_docs = 0
self.sample_to_doc = [] # map sample index to doc and line
# load samples into memory
if on_memory:
@ -71,12 +79,20 @@ class BERTDataset(Dataset):
if line == "":
self.all_docs.append(doc)
doc = []
#remove last added sample because there won't be a subsequent line anymore in the doc
self.sample_to_doc.pop()
else:
#store as one sample
sample = {"doc_id": len(self.all_docs),
"line": len(doc)}
self.sample_to_doc.append(sample)
doc.append(line)
self.corpus_lines = self.corpus_lines + 1
self.corpus_lines = self.corpus_lines + 1
# if last row in file is not empty
if self.all_docs[-1] != doc:
self.all_docs.append(doc)
self.sample_to_doc.pop()
self.num_docs = len(self.all_docs)
@ -159,20 +175,11 @@ class BERTDataset(Dataset):
t2 = ""
assert item < self.corpus_lines
if self.on_memory:
# get the right doc
doc_id = 0
doc_start = 0
doc_end = len(self.all_docs[doc_id]) - 2
while item > doc_end:
doc_id += 1
doc_start = doc_end + 1
doc_end += len(self.all_docs[doc_id]) - 1
# get the right line within doc
line_in_doc = item - doc_start
t1 = self.all_docs[doc_id][line_in_doc]
t2 = self.all_docs[doc_id][line_in_doc + 1]
sample = self.sample_to_doc[item]
t1 = self.all_docs[sample["doc_id"]][sample["line"]]
t2 = self.all_docs[sample["doc_id"]][sample["line"]+1]
# used later to avoid random nextSentence from same doc
self.current_doc = doc_id
self.current_doc = sample["doc_id"]
return t1, t2
else:
if self.line_buffer is None:
@ -297,6 +304,7 @@ def random_word(tokens, tokenizer):
except KeyError:
# For unknown words (should not occur with BPE vocab)
output_label.append(tokenizer.vocab["[UNK]"])
logger.warning("Cannot find token '{}' in vocab. Using [UNK] insetad".format(token))
else:
# no masking token (will be ignored by loss function later)
output_label.append(-1)
@ -468,17 +476,15 @@ def main():
type=int,
default=1,
help="Number of updates steps to accumualte before performing a backward/update pass.")
parser.add_argument('--optimize_on_cpu',
default=False,
action='store_true',
help="Whether to perform optimization and keep the optimizer averages on CPU")
parser.add_argument('--fp16',
default=False,
action='store_true',
help="Whether to use 16-bit float precision instead of 32-bit")
parser.add_argument('--loss_scale',
type=float, default=128,
help='Loss scaling, positive power of 2 values can improve fp16 convergence.')
type = float, default = 0,
help = "Loss scaling to improve fp16 numeric stability. Only used when fp16 set to True.\n"
"0 (default value): dynamic loss scaling.\n"
"Positive power of 2: static loss scaling value.\n")
args = parser.parse_args()
@ -486,14 +492,13 @@ def main():
device = torch.device("cuda" if torch.cuda.is_available() and not args.no_cuda else "cpu")
n_gpu = torch.cuda.device_count()
else:
torch.cuda.set_device(args.local_rank)
device = torch.device("cuda", args.local_rank)
n_gpu = 1
# Initializes the distributed backend which will take care of sychronizing nodes/GPUs
torch.distributed.init_process_group(backend='nccl')
if args.fp16:
logger.info("16-bits training currently not supported in distributed training")
args.fp16 = False # (see https://github.com/pytorch/pytorch/pull/13496)
logger.info("device %s n_gpu %d distributed training %r", device, n_gpu, bool(args.local_rank != -1))
logger.info("device: {} n_gpu: {}, distributed training: {}, 16-bits training: {}".format(
device, n_gpu, bool(args.local_rank != -1), args.fp16))
if args.gradient_accumulation_steps < 1:
raise ValueError("Invalid gradient_accumulation_steps parameter: {}, should be >= 1".format(
@ -531,29 +536,42 @@ def main():
model.half()
model.to(device)
if args.local_rank != -1:
model = torch.nn.parallel.DistributedDataParallel(model, device_ids=[args.local_rank],
output_device=args.local_rank)
try:
from apex.parallel import DistributedDataParallel as DDP
except ImportError:
raise ImportError("Please install apex from https://www.github.com/nvidia/apex to use distributed and fp16 training.")
model = DDP(model)
elif n_gpu > 1:
model = torch.nn.DataParallel(model)
# Prepare optimizer
if args.fp16:
param_optimizer = [(n, param.clone().detach().to('cpu').float().requires_grad_()) \
for n, param in model.named_parameters()]
elif args.optimize_on_cpu:
param_optimizer = [(n, param.clone().detach().to('cpu').requires_grad_()) \
for n, param in model.named_parameters()]
else:
param_optimizer = list(model.named_parameters())
no_decay = ['bias', 'gamma', 'beta']
param_optimizer = list(model.named_parameters())
no_decay = ['bias', 'LayerNorm.bias', 'LayerNorm.weight']
optimizer_grouped_parameters = [
{'params': [p for n, p in param_optimizer if n not in no_decay], 'weight_decay_rate': 0.01},
{'params': [p for n, p in param_optimizer if n in no_decay], 'weight_decay_rate': 0.0}
{'params': [p for n, p in param_optimizer if not any(nd in n for nd in no_decay)], 'weight_decay': 0.01},
{'params': [p for n, p in param_optimizer if any(nd in n for nd in no_decay)], 'weight_decay': 0.0}
]
optimizer = BertAdam(optimizer_grouped_parameters,
lr=args.learning_rate,
warmup=args.warmup_proportion,
t_total=num_train_steps)
if args.fp16:
try:
from apex.optimizers import FP16_Optimizer
from apex.optimizers import FusedAdam
except ImportError:
raise ImportError("Please install apex from https://www.github.com/nvidia/apex to use distributed and fp16 training.")
optimizer = FusedAdam(optimizer_grouped_parameters,
lr=args.learning_rate,
bias_correction=False,
max_grad_norm=1.0)
if args.loss_scale == 0:
optimizer = FP16_Optimizer(optimizer, dynamic_loss_scale=True)
else:
optimizer = FP16_Optimizer(optimizer, static_loss_scale=args.loss_scale)
else:
optimizer = BertAdam(optimizer_grouped_parameters,
lr=args.learning_rate,
warmup=args.warmup_proportion,
t_total=num_train_steps)
global_step = 0
if args.do_train:
@ -580,33 +598,22 @@ def main():
loss = model(input_ids, segment_ids, input_mask, lm_label_ids, is_next)
if n_gpu > 1:
loss = loss.mean() # mean() to average on multi-gpu.
if args.fp16 and args.loss_scale != 1.0:
# rescale loss for fp16 training
# see https://docs.nvidia.com/deeplearning/sdk/mixed-precision-training/index.html
loss = loss * args.loss_scale
if args.gradient_accumulation_steps > 1:
loss = loss / args.gradient_accumulation_steps
loss.backward()
if args.fp16:
optimizer.backward(loss)
else:
loss.backward()
tr_loss += loss.item()
nb_tr_examples += input_ids.size(0)
nb_tr_steps += 1
if (step + 1) % args.gradient_accumulation_steps == 0:
if args.fp16 or args.optimize_on_cpu:
if args.fp16 and args.loss_scale != 1.0:
# scale down gradients for fp16 training
for param in model.parameters():
param.grad.data = param.grad.data / args.loss_scale
is_nan = set_optimizer_params_grad(param_optimizer, model.named_parameters(), test_nan=True)
if is_nan:
logger.info("FP16 TRAINING: Nan in gradients, reducing loss scaling")
args.loss_scale = args.loss_scale / 2
model.zero_grad()
continue
optimizer.step()
copy_optimizer_params_to_model(model.named_parameters(), param_optimizer)
else:
optimizer.step()
model.zero_grad()
# modify learning rate with special warm up BERT uses
lr_this_step = args.learning_rate * warmup_linear(global_step/num_train_steps, args.warmup_proportion)
for param_group in optimizer.param_groups:
param_group['lr'] = lr_this_step
optimizer.step()
optimizer.zero_grad()
global_step += 1
logger.info("** ** * Saving fine - tuned model ** ** * ")
@ -639,36 +646,5 @@ def accuracy(out, labels):
return np.sum(outputs == labels)
def copy_optimizer_params_to_model(named_params_model, named_params_optimizer):
""" Utility function for optimize_on_cpu and 16-bits training.
Copy the parameters optimized on CPU/RAM back to the model on GPU
"""
for (name_opti, param_opti), (name_model, param_model) in zip(named_params_optimizer, named_params_model):
if name_opti != name_model:
logger.error("name_opti != name_model: {} {}".format(name_opti, name_model))
raise ValueError
param_model.data.copy_(param_opti.data)
def set_optimizer_params_grad(named_params_optimizer, named_params_model, test_nan=False):
""" Utility function for optimize_on_cpu and 16-bits training.
Copy the gradient of the GPU parameters to the CPU/RAMM copy of the model
"""
is_nan = False
for (name_opti, param_opti), (name_model, param_model) in zip(named_params_optimizer, named_params_model):
if name_opti != name_model:
logger.error("name_opti != name_model: {} {}".format(name_opti, name_model))
raise ValueError
if param_model.grad is not None:
if test_nan and torch.isnan(param_model.grad).sum() > 0:
is_nan = True
if param_opti.grad is None:
param_opti.grad = torch.nn.Parameter(param_opti.data.new().resize_(*param_opti.data.size()))
param_opti.grad.data.copy_(param_model.grad.data)
else:
param_opti.grad = None
return is_nan
if __name__ == "__main__":
main()