File size: 22,568 Bytes
6fc683c |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 |
# Copyright (c) 2022 Microsoft
# Licensed under The MIT License [see LICENSE for details]
# Copyright (c) Facebook, Inc. and its affiliates.
#
# This source code is licensed under the MIT license found in the
# LICENSE file in the root directory of this source tree.
import logging
from typing import Dict, List, Optional, Tuple
import torch
from fairseq import distributed_utils, utils
from fairseq.distributed import utils as fsdp_wrap
from fairseq.models import (
FairseqEncoder,
FairseqEncoderDecoderModel,
register_model,
register_model_architecture,
)
from fairseq.models.transformer import Embedding
from fairseq.modules import PositionalEmbedding
from torch import Tensor
from torchscale.architecture.config import DecoderConfig, EncoderConfig
from torchscale.architecture.encoder import Encoder
from .language_modeling import LMDecoder as MTDecoder
logger = logging.getLogger(__name__)
DEFAULT_MAX_SOURCE_POSITIONS = 1024
DEFAULT_MAX_TARGET_POSITIONS = 1024
DEFAULT_MIN_PARAMS_TO_WRAP = int(1e8)
@register_model("mt")
class TranslationModel(FairseqEncoderDecoderModel):
def __init__(self, args, encoder, decoder):
super().__init__(encoder, decoder)
self.args = args
@staticmethod
def add_args(parser):
"""Add model-specific arguments to the parser."""
# fmt: off
parser.add_argument('--activation-fn',
choices=utils.get_available_activation_fns(),
help='activation function to use')
parser.add_argument('--dropout', type=float, metavar='D',
help='dropout probability')
parser.add_argument('--attention-dropout', type=float, metavar='D',
help='dropout probability for attention weights')
parser.add_argument('--activation-dropout', '--relu-dropout', type=float, metavar='D',
help='dropout probability after activation in FFN.')
parser.add_argument('--encoder-embed-path', type=str, metavar='STR',
help='path to pre-trained encoder embedding')
parser.add_argument('--encoder-embed-dim', type=int, metavar='N',
help='encoder embedding dimension')
parser.add_argument('--encoder-ffn-embed-dim', type=int, metavar='N',
help='encoder embedding dimension for FFN')
parser.add_argument('--encoder-layers', type=int, metavar='N',
help='num encoder layers')
parser.add_argument('--encoder-attention-heads', type=int, metavar='N',
help='num encoder attention heads')
parser.add_argument('--encoder-normalize-before', action='store_true',
help='apply layernorm before each encoder block')
parser.add_argument('--encoder-learned-pos', action='store_true',
help='use learned positional embeddings in the encoder')
parser.add_argument('--decoder-embed-path', type=str, metavar='STR',
help='path to pre-trained decoder embedding')
parser.add_argument('--decoder-embed-dim', type=int, metavar='N',
help='decoder embedding dimension')
parser.add_argument('--decoder-ffn-embed-dim', type=int, metavar='N',
help='decoder embedding dimension for FFN')
parser.add_argument('--decoder-layers', type=int, metavar='N',
help='num decoder layers')
parser.add_argument('--decoder-attention-heads', type=int, metavar='N',
help='num decoder attention heads')
parser.add_argument('--decoder-learned-pos', action='store_true',
help='use learned positional embeddings in the decoder')
parser.add_argument('--decoder-normalize-before', action='store_true',
help='apply layernorm before each decoder block')
parser.add_argument('--decoder-output-dim', type=int, metavar='N',
help='decoder output dimension (extra linear layer '
'if different from decoder embed dim')
parser.add_argument('--share-decoder-input-output-embed', action='store_true',
help='share decoder input and output embeddings')
parser.add_argument('--share-all-embeddings', action='store_true',
help='share encoder, decoder and output embeddings'
' (requires shared dictionary and embed dim)')
parser.add_argument('--no-token-positional-embeddings', default=False, action='store_true',
help='if set, disables positional embeddings (outside self attention)')
parser.add_argument('--adaptive-softmax-cutoff', metavar='EXPR',
help='comma separated list of adaptive softmax cutoff points. '
'Must be used with adaptive_loss criterion'),
parser.add_argument('--adaptive-softmax-dropout', type=float, metavar='D',
help='sets adaptive softmax dropout for the tail projections')
parser.add_argument('--layernorm-embedding', action='store_true',
help='add layernorm to embedding')
parser.add_argument('--no-scale-embedding', action='store_true',
help='if True, dont scale embeddings')
parser.add_argument('--checkpoint-activations', action='store_true',
help='checkpoint activations at each layer, which saves GPU '
'memory usage at the cost of some additional compute')
parser.add_argument('--offload-activations', action='store_true',
help='checkpoint activations at each layer, then save to gpu. Sets --checkpoint-activations.')
# args for "Cross+Self-Attention for Transformer Models" (Peitz et al., 2019)
parser.add_argument('--no-cross-attention', default=False, action='store_true',
help='do not perform cross-attention')
parser.add_argument('--cross-self-attention', default=False, action='store_true',
help='perform cross+self-attention')
# args for "Reducing Transformer Depth on Demand with Structured Dropout" (Fan et al., 2019)
parser.add_argument('--encoder-layerdrop', type=float, metavar='D', default=0,
help='LayerDrop probability for encoder')
parser.add_argument('--decoder-layerdrop', type=float, metavar='D', default=0,
help='LayerDrop probability for decoder')
parser.add_argument('--encoder-layers-to-keep', default=None,
help='which layers to *keep* when pruning as a comma-separated list')
parser.add_argument('--decoder-layers-to-keep', default=None,
help='which layers to *keep* when pruning as a comma-separated list')
# args for Training with Quantization Noise for Extreme Model Compression ({Fan*, Stock*} et al., 2020)
parser.add_argument('--quant-noise-pq', type=float, metavar='D', default=0,
help='iterative PQ quantization noise at training time')
parser.add_argument('--quant-noise-pq-block-size', type=int, metavar='D', default=8,
help='block size of quantization noise at training time')
parser.add_argument('--quant-noise-scalar', type=float, metavar='D', default=0,
help='scalar quantization noise and scalar quantization at training time')
# args for Fully Sharded Data Parallel (FSDP) training
parser.add_argument(
'--min-params-to-wrap', type=int, metavar='D', default=DEFAULT_MIN_PARAMS_TO_WRAP,
help=(
'minimum number of params for a layer to be wrapped with FSDP() when '
'training with --ddp-backend=fully_sharded. Smaller values will '
'improve memory efficiency, but may make torch.distributed '
'communication less efficient due to smaller input sizes. This option '
'is set to 0 (i.e., always wrap) when --checkpoint-activations or '
'--offload-activations are passed.'
)
)
# args for mixture-of-expert layers
parser.add_argument('--moe-freq', type=int, metavar='D', default=0,
help='Frequency at which we insert MoE Transformer layers')
parser.add_argument('--encoder-moe-freq', type=int, metavar='D', default=0,
help='Frequency at which we insert MoE Transformer encoder layers')
parser.add_argument('--decoder-moe-freq', type=int, metavar='D', default=0,
help='Frequency at which we insert MoE Transformer decoder layers')
parser.add_argument('--moe-expert-count', type=int, metavar='D', default=0,
help='Number of experts in each MoE Layer')
parser.add_argument('--moe-gating-use-fp32', default=False, action='store_true',
help="Use FP32 computations in MoE top2 gating function")
parser.add_argument('--moe-second-expert-policy', type=str, default='sampling',
help="policy for second expert, options: all/sampling/random")
parser.add_argument(
'--moe-normalize-gate-prob-before-dropping', default=False, action='store_true',
help=(
"whether to normalize gate probs before or after dropping experts "
"for capacity and randomization"
)
)
parser.add_argument('--moe-expert-ffn-dim', type=int, default=0,
help="MoE Expert FFN dimension")
parser.add_argument('--moe-top1-expert', default=False, action='store_true',
help="Use top1 gate instead of top2")
parser.add_argument(
'--moe-eval-capacity-token-fraction', type=float, default=0.25,
help=(
"Fraction of tokens as capacity during validation"
"if set to negative, use same as training. range: (0.0, 1.0]."
)
)
parser.add_argument('--moe-normalize-expert-grad', type=str, default='world_size',
help="Divide expert gradients by (1) 'world_size' (2) 'sqrt_world_size'")
parser.add_argument('--use-moe-pad-mask', default=False, action='store_true',
help="Don't route padding tokens to any expert")
parser.add_argument('--use-xmoe', default=False, action='store_true',
help="Enable X-Moe")
parser.add_argument('--freeze-moe', default=False, action='store_true',
help="Freeze MoE Params")
parser.add_argument('--deepnorm', default=False, action='store_true',
help="Enable DeepNorm")
parser.add_argument('--subln', default=False, action='store_true',
help="Enable SubLN")
parser.add_argument('--pretrained-dense-mt-model-path', type=str, default='')
# args for pseudo-MoE layers
parser.add_argument('--alternate-ffn-embed-dim', type=int, default=0,
help="FFN embed dim of alternate pseudo-MoE blocks")
parser.add_argument('--rel-pos-buckets', type=int, default=0,
help='')
parser.add_argument('--max-rel-pos', type=int, default=0,
help='')
# fmt: on
@classmethod
def build_model(cls, args, task):
"""Build a new model instance."""
# make sure all arguments are present in older models
base_architecture(args)
if getattr(args, "max_source_positions", None) is None:
args.max_source_positions = DEFAULT_MAX_SOURCE_POSITIONS
if getattr(args, "max_target_positions", None) is None:
args.max_target_positions = DEFAULT_MAX_TARGET_POSITIONS
args.ddp_rank = distributed_utils.get_data_parallel_rank()
src_dict, tgt_dict = task.source_dictionary, task.target_dictionary
if args.share_all_embeddings:
if src_dict != tgt_dict:
raise ValueError("--share-all-embeddings requires a joined dictionary")
if args.encoder_embed_dim != args.decoder_embed_dim:
raise ValueError(
"--share-all-embeddings requires --encoder-embed-dim to match --decoder-embed-dim"
)
if args.decoder_embed_path and (
args.decoder_embed_path != args.encoder_embed_path
):
raise ValueError(
"--share-all-embeddings not compatible with --decoder-embed-path"
)
encoder_embed_tokens = cls.build_embedding(
args, src_dict, args.encoder_embed_dim, args.encoder_embed_path
)
decoder_embed_tokens = encoder_embed_tokens
args.share_decoder_input_output_embed = True
else:
encoder_embed_tokens = cls.build_embedding(
args, src_dict, args.encoder_embed_dim, args.encoder_embed_path
)
decoder_embed_tokens = cls.build_embedding(
args, tgt_dict, args.decoder_embed_dim, args.decoder_embed_path
)
if getattr(args, "offload_activations", False):
args.checkpoint_activations = True # offloading implies checkpointing
encoder_embed_positions = (
PositionalEmbedding(
args.max_source_positions,
args.encoder_embed_dim,
src_dict.pad(),
learned=args.encoder_learned_pos,
)
if not args.no_token_positional_embeddings
else None
)
decoder_embed_positions = (
PositionalEmbedding(
args.max_target_positions,
args.decoder_embed_dim,
tgt_dict.pad(),
learned=args.decoder_learned_pos,
)
if not args.no_token_positional_embeddings
else None
)
if args.share_decoder_input_output_embed:
output_projection = torch.nn.Linear(
decoder_embed_tokens.weight.shape[1],
decoder_embed_tokens.weight.shape[0],
bias=False,
)
output_projection.weight = decoder_embed_tokens.weight
else:
output_projection = torch.nn.Linear(
args.decoder_embed_dim, len(tgt_dict), bias=False
)
torch.nn.init.normal_(
output_projection.weight, mean=0, std=args.decoder_embed_dim**-0.5
)
encoder = cls.build_encoder(
args,
encoder_embed_tokens,
encoder_embed_positions,
src_dict,
)
decoder = cls.build_decoder(
args,
decoder_embed_tokens,
decoder_embed_positions,
output_projection,
tgt_dict,
)
if not args.share_all_embeddings:
min_params_to_wrap = getattr(
args, "min_params_to_wrap", DEFAULT_MIN_PARAMS_TO_WRAP
)
# fsdp_wrap is a no-op when --ddp-backend != fully_sharded
encoder = fsdp_wrap(encoder, min_num_params=min_params_to_wrap)
decoder = fsdp_wrap(decoder, min_num_params=min_params_to_wrap)
return cls(args, encoder, decoder)
@classmethod
def build_embedding(cls, args, dictionary, embed_dim, path=None):
num_embeddings = len(dictionary)
padding_idx = dictionary.pad()
emb = Embedding(num_embeddings, embed_dim, padding_idx)
# if provided, load from preloaded dictionaries
if path:
embed_dict = utils.parse_embedding(path)
utils.load_embedding(embed_dict, dictionary, emb)
return emb
@classmethod
def build_encoder(cls, args, embed_tokens, embed_positions, dictionary):
config = EncoderConfig()
config.override(args)
return MTEncoder(
config,
embed_tokens,
embed_positions,
is_encoder_decoder=True,
dictionary=dictionary,
)
@classmethod
def build_decoder(
cls, args, embed_tokens, embed_positions, output_projection, dictionary
):
config = DecoderConfig()
config.override(args)
return MTDecoder(
config,
embed_tokens,
embed_positions,
output_projection,
is_encoder_decoder=True,
dictionary=dictionary,
)
def forward(
self,
src_tokens,
src_lengths,
prev_output_tokens,
return_all_hiddens: bool = False,
features_only: bool = False,
**kwargs
):
encoder_out = self.encoder(src_tokens, return_all_hiddens=return_all_hiddens)
decoder_out = self.decoder(
prev_output_tokens,
encoder_out=encoder_out,
features_only=features_only,
return_all_hiddens=return_all_hiddens,
)
return decoder_out
def get_normalized_probs(
self,
net_output: Tuple[Tensor, Optional[Dict[str, List[Optional[Tensor]]]]],
log_probs: bool,
sample: Optional[Dict[str, Tensor]] = None,
):
"""Get normalized probabilities (or log probs) from a net's output."""
return self.get_normalized_probs_scriptable(net_output, log_probs, sample)
class MTEncoder(Encoder, FairseqEncoder):
def forward(self, src_tokens, **kwargs):
self_attn_padding_mask = src_tokens.eq(self.dictionary.pad())
return super().forward(
src_tokens=src_tokens, encoder_padding_mask=self_attn_padding_mask, **kwargs
)
def reorder_encoder_out(self, encoder_out, new_order):
new_encoder_out = encoder_out["encoder_out"].index_select(1, new_order)
new_encoder_embedding = encoder_out["encoder_embedding"].index_select(
0, new_order
)
new_encoder_padding_mask = encoder_out["encoder_padding_mask"].index_select(
0, new_order
)
encoder_states = encoder_out["encoder_states"]
if len(encoder_states) > 0:
for idx, state in enumerate(encoder_states):
encoder_states[idx] = state.index_select(1, new_order)
return {
"encoder_out": new_encoder_out, # T x B x C
"encoder_padding_mask": new_encoder_padding_mask,
"encoder_embedding": new_encoder_embedding, # B x T x C
"encoder_states": encoder_states, # List[T x B x C]
}
def max_positions(self):
return self.embed_positions.max_positions
@register_model_architecture("mt", "mt_base")
def base_architecture(args):
args.encoder_embed_path = getattr(args, "encoder_embed_path", None)
args.encoder_embed_dim = getattr(args, "encoder_embed_dim", 512)
args.encoder_ffn_embed_dim = getattr(args, "encoder_ffn_embed_dim", 2048)
args.encoder_layers = getattr(args, "encoder_layers", 6)
args.encoder_attention_heads = getattr(args, "encoder_attention_heads", 8)
args.encoder_normalize_before = getattr(args, "encoder_normalize_before", False)
args.encoder_learned_pos = getattr(args, "encoder_learned_pos", False)
args.decoder_embed_path = getattr(args, "decoder_embed_path", None)
args.decoder_embed_dim = getattr(args, "decoder_embed_dim", args.encoder_embed_dim)
args.decoder_ffn_embed_dim = getattr(
args, "decoder_ffn_embed_dim", args.encoder_ffn_embed_dim
)
args.decoder_layers = getattr(args, "decoder_layers", 6)
args.decoder_attention_heads = getattr(args, "decoder_attention_heads", 8)
args.decoder_normalize_before = getattr(args, "decoder_normalize_before", False)
args.decoder_learned_pos = getattr(args, "decoder_learned_pos", False)
args.attention_dropout = getattr(args, "attention_dropout", 0.0)
args.activation_dropout = getattr(args, "activation_dropout", 0.0)
args.activation_fn = getattr(args, "activation_fn", "relu")
args.dropout = getattr(args, "dropout", 0.1)
args.adaptive_softmax_cutoff = getattr(args, "adaptive_softmax_cutoff", None)
args.adaptive_softmax_dropout = getattr(args, "adaptive_softmax_dropout", 0)
args.share_decoder_input_output_embed = getattr(
args, "share_decoder_input_output_embed", False
)
args.share_all_embeddings = getattr(args, "share_all_embeddings", False)
args.no_token_positional_embeddings = getattr(
args, "no_token_positional_embeddings", False
)
args.adaptive_input = getattr(args, "adaptive_input", False)
args.no_cross_attention = getattr(args, "no_cross_attention", False)
args.cross_self_attention = getattr(args, "cross_self_attention", False)
args.decoder_output_dim = getattr(
args, "decoder_output_dim", args.decoder_embed_dim
)
args.decoder_input_dim = getattr(args, "decoder_input_dim", args.decoder_embed_dim)
args.no_scale_embedding = getattr(args, "no_scale_embedding", False)
args.layernorm_embedding = getattr(args, "layernorm_embedding", False)
args.tie_adaptive_weights = getattr(args, "tie_adaptive_weights", False)
args.checkpoint_activations = getattr(args, "checkpoint_activations", False)
args.offload_activations = getattr(args, "offload_activations", False)
if args.offload_activations:
args.checkpoint_activations = True
args.encoder_layers_to_keep = getattr(args, "encoder_layers_to_keep", None)
args.decoder_layers_to_keep = getattr(args, "decoder_layers_to_keep", None)
args.encoder_layerdrop = getattr(args, "encoder_layerdrop", 0)
args.decoder_layerdrop = getattr(args, "decoder_layerdrop", 0)
args.quant_noise_pq = getattr(args, "quant_noise_pq", 0)
args.quant_noise_pq_block_size = getattr(args, "quant_noise_pq_block_size", 8)
args.quant_noise_scalar = getattr(args, "quant_noise_scalar", 0)
args.is_moe = getattr(args, "is_moe", False)
args.selected_expert_count = getattr(args, "selected_expert_count", 2)
|