update apex fp16 implementation

This commit is contained in:
jamin 2019-08-30 13:54:00 +09:00
parent caf1d116a6
commit c8731b9583

View File

@ -1,22 +1,20 @@
from argparse import ArgumentParser
from pathlib import Path
import os
import torch
import logging
import json
import logging
import random
import numpy as np
from argparse import ArgumentParser
from collections import namedtuple
from pathlib import Path
from tempfile import TemporaryDirectory
import numpy as np
import torch
from torch.utils.data import DataLoader, Dataset, RandomSampler
from torch.utils.data.distributed import DistributedSampler
from tqdm import tqdm
from pytorch_transformers import WEIGHTS_NAME, CONFIG_NAME
from pytorch_transformers.modeling_bert import BertForPreTraining
from pytorch_transformers.tokenization_bert import BertTokenizer
from pytorch_transformers.optimization import AdamW, WarmupLinearSchedule
from pytorch_transformers.tokenization_bert import BertTokenizer
InputFeatures = namedtuple("InputFeatures", "input_ids input_mask segment_ids lm_label_ids is_next")
@ -72,16 +70,16 @@ class PregeneratedDataset(Dataset):
if reduce_memory:
self.temp_dir = TemporaryDirectory()
self.working_dir = Path(self.temp_dir.name)
input_ids = np.memmap(filename=self.working_dir/'input_ids.memmap',
input_ids = np.memmap(filename=self.working_dir / 'input_ids.memmap',
mode='w+', dtype=np.int32, shape=(num_samples, seq_len))
input_masks = np.memmap(filename=self.working_dir/'input_masks.memmap',
input_masks = np.memmap(filename=self.working_dir / 'input_masks.memmap',
shape=(num_samples, seq_len), mode='w+', dtype=np.bool)
segment_ids = np.memmap(filename=self.working_dir/'segment_ids.memmap',
segment_ids = np.memmap(filename=self.working_dir / 'segment_ids.memmap',
shape=(num_samples, seq_len), mode='w+', dtype=np.bool)
lm_label_ids = np.memmap(filename=self.working_dir/'lm_label_ids.memmap',
lm_label_ids = np.memmap(filename=self.working_dir / 'lm_label_ids.memmap',
shape=(num_samples, seq_len), mode='w+', dtype=np.int32)
lm_label_ids[:] = -1
is_nexts = np.memmap(filename=self.working_dir/'is_nexts.memmap',
is_nexts = np.memmap(filename=self.working_dir / 'is_nexts.memmap',
shape=(num_samples,), mode='w+', dtype=np.bool)
else:
input_ids = np.zeros(shape=(num_samples, seq_len), dtype=np.int32)
@ -125,7 +123,8 @@ def main():
parser = ArgumentParser()
parser.add_argument('--pregenerated_data', type=Path, required=True)
parser.add_argument('--output_dir', type=Path, required=True)
parser.add_argument("--bert_model", type=str, required=True, help="Bert pre-trained model selected in the list: bert-base-uncased, "
parser.add_argument("--bert_model", type=str, required=True,
help="Bert pre-trained model selected in the list: bert-base-uncased, "
"bert-large-uncased, bert-base-cased, bert-base-multilingual, bert-base-chinese.")
parser.add_argument("--do_lower_case", action="store_true")
parser.add_argument("--reduce_memory", action="store_true",
@ -153,14 +152,14 @@ def main():
parser.add_argument('--loss_scale',
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")
parser.add_argument("--warmup_steps",
default=0,
"0 (default value): dynamic loss scaling.\n"
"Positive power of 2: static loss scaling value.\n")
parser.add_argument("--warmup_steps",
default=0,
type=int,
help="Linear warmup over warmup_steps.")
parser.add_argument("--adam_epsilon",
default=1e-8,
parser.add_argument("--adam_epsilon",
default=1e-8,
type=float,
help="Epsilon for Adam optimizer.")
parser.add_argument("--learning_rate",
@ -207,7 +206,7 @@ def main():
if args.gradient_accumulation_steps < 1:
raise ValueError("Invalid gradient_accumulation_steps parameter: {}, should be >= 1".format(
args.gradient_accumulation_steps))
args.gradient_accumulation_steps))
args.train_batch_size = args.train_batch_size // args.gradient_accumulation_steps
@ -235,8 +234,9 @@ def main():
# Prepare model
model = BertForPreTraining.from_pretrained(args.bert_model)
if args.fp16:
model.half()
# We don't need to manually call model.half() following Apex's recommend
# if args.fp16:
# model.half()
model.to(device)
if args.local_rank != -1:
try:
@ -257,25 +257,36 @@ def main():
{'params': [p for n, p in param_optimizer if any(nd in n for nd in no_decay)], 'weight_decay': 0.0}
]
optimizer = AdamW(optimizer_grouped_parameters, lr=args.learning_rate, eps=args.adam_epsilon)
scheduler = WarmupLinearSchedule(optimizer, warmup_steps=args.warmup_steps,
t_total=num_train_optimization_steps)
if args.fp16:
try:
from apex.optimizers import FP16_Optimizer
from apex.optimizers import FusedAdam
# from apex.optimizers import FP16_Optimizer
# from apex.optimizers import FusedAdam
from apex import amp
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 = AdamW(optimizer_grouped_parameters, lr=args.learning_rate, eps=args.adam_epsilon)
scheduler = WarmupLinearSchedule(optimizer, warmup_steps=args.warmup_steps, t_total=num_train_optimization_steps)
# This below line of code is the main upgrade of Apex Fp16 implementation. I chose opt_leve="01"
# because it's recommended for typical use by Apex. We can make it configured
model, optimizer = amp.initialize(model, optimizer, opt_level="O1")
# We don't need to use FP16_Optimizer wrapping over FusedAdam as well. Now Apex supports all Pytorch Optimizer
# 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 = AdamW(optimizer_grouped_parameters, lr=args.learning_rate, eps=args.adam_epsilon)
# scheduler = WarmupLinearSchedule(optimizer, warmup_steps=args.warmup_steps, t_total=num_train_optimization_steps)
global_step = 0
logging.info("***** Running training *****")
@ -300,11 +311,14 @@ def main():
outputs = model(input_ids, segment_ids, input_mask, lm_label_ids, is_next)
loss = outputs[0]
if n_gpu > 1:
loss = loss.mean() # mean() to average on multi-gpu.
loss = loss.mean() # mean() to average on multi-gpu.
if args.gradient_accumulation_steps > 1:
loss = loss / args.gradient_accumulation_steps
if args.fp16:
optimizer.backward(loss)
# I depricate FP16_Optimizer's backward func and replace as Apex document
# optimizer.backward(loss)
with amp.scale_loss(loss, optimizer) as scaled_loss:
scaled_loss.backward()
else:
loss.backward()
tr_loss += loss.item()
@ -322,7 +336,8 @@ def main():
# Save a trained model
if args.local_rank == -1 or torch.distributed.get_rank() == 0:
logging.info("** ** * Saving fine-tuned model ** ** * ")
model_to_save = model.module if hasattr(model, 'module') else model # Take care of distributed/parallel training
model_to_save = model.module if hasattr(model,
'module') else model # Take care of distributed/parallel training
model_to_save.save_pretrained(args.output_dir)
tokenizer.save_pretrained(args.output_dir)