This commit is contained in:
josc146
2024-05-28 22:35:47 +08:00
parent 3488d22d22
commit f05a4acb04
138 changed files with 29047 additions and 334 deletions

View File

@@ -0,0 +1,14 @@
# -*- coding: utf-8 -*-
from transformers import AutoConfig, AutoModel, AutoModelForCausalLM
from fla.models.transformer.configuration_transformer import TransformerConfig
from fla.models.transformer.modeling_transformer import (
TransformerForCausalLM, TransformerModel)
AutoConfig.register(TransformerConfig.model_type, TransformerConfig)
AutoModel.register(TransformerConfig, TransformerModel)
AutoModelForCausalLM.register(TransformerConfig, TransformerForCausalLM)
__all__ = ['TransformerConfig', 'TransformerForCausalLM', 'TransformerModel']

View File

@@ -0,0 +1,61 @@
# -*- coding: utf-8 -*-
from typing import Optional
from transformers.configuration_utils import PretrainedConfig
class TransformerConfig(PretrainedConfig):
model_type = 'transformer'
keys_to_ignore_at_inference = ['past_key_values']
def __init__(
self,
vocab_size: int = 32000,
hidden_size: int = 2048,
hidden_ratio: Optional[int] = 4,
intermediate_size: Optional[int] = None,
num_hidden_layers: int = 24,
num_heads: int = 32,
num_kv_heads: int = None,
hidden_act: str = "swish",
max_position_embeddings: int = 2048,
initializer_range: float = 0.02,
elementwise_affine: Optional[bool] = True,
norm_eps: float = 1e-6,
use_cache: bool = True,
pad_token_id: int = None,
bos_token_id: int = 1,
eos_token_id: int = 2,
tie_word_embeddings: bool = False,
attention_bias: bool = False,
fuse_norm: bool = True,
fuse_cross_entropy: bool = True,
**kwargs,
):
self.vocab_size = vocab_size
self.max_position_embeddings = max_position_embeddings
self.hidden_size = hidden_size
self.hidden_ratio = hidden_ratio
self.intermediate_size = intermediate_size
self.num_hidden_layers = num_hidden_layers
self.num_heads = num_heads
self.num_kv_heads = num_kv_heads
self.hidden_act = hidden_act
self.initializer_range = initializer_range
self.elementwise_affine = elementwise_affine
self.norm_eps = norm_eps
self.use_cache = use_cache
self.attention_bias = attention_bias
self.fuse_cross_entropy = fuse_cross_entropy
self.fuse_norm = fuse_norm
super().__init__(
pad_token_id=pad_token_id,
bos_token_id=bos_token_id,
eos_token_id=eos_token_id,
tie_word_embeddings=tie_word_embeddings,
**kwargs,
)

View File

@@ -0,0 +1,522 @@
# -*- coding: utf-8 -*-
from __future__ import annotations
import math
import warnings
from typing import List, Optional, Tuple, Union
import torch
import torch.nn as nn
import torch.nn.functional as F
import torch.utils.checkpoint
from einops import rearrange
from transformers.activations import ACT2FN
from transformers.cache_utils import Cache, DynamicCache
from transformers.modeling_outputs import (BaseModelOutputWithPast,
CausalLMOutputWithPast)
from transformers.modeling_utils import PreTrainedModel
from transformers.utils import logging
from fla.models.transformer.configuration_transformer import TransformerConfig
from fla.modules import FusedCrossEntropyLoss, RMSNorm, RotaryEmbedding
from fla.modules.activations import swiglu_linear
try:
from flash_attn import flash_attn_func, flash_attn_varlen_func
from flash_attn.bert_padding import (index_first_axis, pad_input,
unpad_input)
except ImportError:
warnings.warn("Flash Attention is not installed. Please install it via `pip install flash-attn --no-build-isolation`")
flash_attn_func = None
logger = logging.get_logger(__name__)
class TransformerAttention(nn.Module):
def __init__(
self,
config: TransformerConfig,
layer_idx: Optional[int] = None,
**kwargs
):
super().__init__()
self.config = config
self.layer_idx = layer_idx
self.num_heads = config.num_heads
if config.num_kv_heads is None:
self.num_kv_heads = self.num_heads
else:
self.num_kv_heads = config.num_kv_heads
self.num_kv_groups = config.num_heads // self.num_kv_heads
self.hidden_size = config.hidden_size
self.head_dim = self.hidden_size // self.num_heads
self.kv_dim = self.num_kv_heads * self.head_dim
self.kv_dim = self.num_kv_heads * self.head_dim
self.max_position_embeddings = config.max_position_embeddings
self.q_proj = nn.Linear(self.hidden_size, self.hidden_size, bias=False)
self.k_proj = nn.Linear(self.hidden_size, self.kv_dim, bias=False)
self.v_proj = nn.Linear(self.hidden_size, self.kv_dim, bias=False)
self.o_proj = nn.Linear(self.hidden_size, self.hidden_size, bias=False)
self.rotary = RotaryEmbedding(self.head_dim)
self.apply(self._initialize_weights)
def _initialize_weights(self, module: nn.Module):
if getattr(module, "_is_hf_initialized", False):
return
if isinstance(module, nn.Linear):
nn.init.xavier_uniform_(module.weight, gain=2 ** -2.5)
if module.bias is not None:
nn.init.zeros_(module.bias)
module._is_hf_initialized = True
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.LongTensor] = None,
past_key_values: Optional[Cache] = None,
output_attentions: bool = False,
use_cache: bool = False,
**kwargs,
) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor]]]:
batch_size, q_len, _ = hidden_states.size()
q = rearrange(self.q_proj(hidden_states), '... (h d) -> ... h d', h=self.num_heads)
k = rearrange(self.k_proj(hidden_states), '... (h d) -> ... h d', h=self.num_kv_heads)
v = rearrange(self.v_proj(hidden_states), 'b t (h d) -> b h t d', h=self.num_kv_heads)
seqlen_offset = 0
if past_key_values is not None:
seqlen_offset = past_key_values.get_seq_length(self.layer_idx)
if attention_mask is not None:
# to deliminate the offsets of padding tokens
seqlen_offset = seqlen_offset + attention_mask.sum(-1) - attention_mask.shape[-1]
q, k = self.rotary(q, k, seqlen_offset, self.max_position_embeddings)
k = rearrange(k, 'b t h d -> b h t d')
if past_key_values is not None:
k, v = past_key_values.update(k, v, self.layer_idx)
k, v = rearrange(k, 'b h t d -> b t h d'), rearrange(v, 'b h t d -> b t h d')
if self.num_kv_groups > 1:
k = rearrange(k.unsqueeze(-2).repeat(1, 1, 1, self.num_kv_groups, 1), 'b t h g d -> b t (h g) d')
v = rearrange(v.unsqueeze(-2).repeat(1, 1, 1, self.num_kv_groups, 1), 'b t h g d -> b t (h g) d')
if flash_attn_func is None:
raise ImportError("Please install Flash Attention via `pip install flash-attn --no-build-isolation` first")
# Contains at least one padding token in the sequence
if attention_mask is not None:
q, k, v, indices_q, cu_seq_lens, max_seq_lens = self._upad_input(q, k, v, attention_mask, q_len)
cu_seqlens_q, cu_seqlens_k = cu_seq_lens
max_seqlen_q, max_seqlen_k = max_seq_lens
o = flash_attn_varlen_func(
q, k, v,
cu_seqlens_q=cu_seqlens_q,
cu_seqlens_k=cu_seqlens_k,
max_seqlen_q=max_seqlen_q,
max_seqlen_k=max_seqlen_k,
causal=True
)
o = pad_input(o, indices_q, batch_size, q_len)
else:
o = flash_attn_func(q, k, v, causal=True)
o = o.reshape(batch_size, q_len, self.hidden_size)
o = self.o_proj(o)
if not output_attentions:
attentions = None
return o, attentions, past_key_values
def _upad_input(self, q, k, v, attention_mask, q_len):
seqlens = attention_mask.sum(-1, dtype=torch.int32)
indices_k = torch.nonzero(attention_mask.flatten(), as_tuple=False).flatten()
max_seqlen_k = seqlens.max().item()
cu_seqlens_k = F.pad(torch.cumsum(seqlens, dim=0, dtype=torch.int32), (1, 0))
batch_size, seq_len, num_key_value_heads, head_dim = k.shape
k = index_first_axis(k.reshape(batch_size * seq_len, num_key_value_heads, head_dim), indices_k)
v = index_first_axis(v.reshape(batch_size * seq_len, num_key_value_heads, head_dim), indices_k)
if q_len == seq_len:
q = index_first_axis(q.reshape(batch_size * seq_len, self.num_heads, head_dim), indices_k)
cu_seqlens_q = cu_seqlens_k
max_seqlen_q = max_seqlen_k
indices_q = indices_k
elif q_len == 1:
max_seqlen_q = 1
# There is a memcpy here, that is very bad.
cu_seqlens_q = torch.arange(batch_size + 1, dtype=torch.int32, device=q.device)
indices_q = cu_seqlens_q[:-1]
q = q.squeeze(1)
else:
# The -q_len: slice assumes left padding.
attention_mask = attention_mask[:, -q_len:]
q, indices_q, cu_seqlens_q, max_seqlen_q = unpad_input(q, attention_mask)
return q, k, v, indices_q, (cu_seqlens_q, cu_seqlens_k), (max_seqlen_q, max_seqlen_k)
class TransformerMLP(nn.Module):
def __init__(
self,
hidden_size: int,
hidden_ratio: Optional[int] = None,
intermediate_size: Optional[int] = None,
hidden_act: str = 'swish'
) -> TransformerMLP:
super().__init__()
self.hidden_size = hidden_size
# the final number of params is `hidden_ratio * hidden_size^2`
# `intermediate_size` is chosen to be a multiple of 256 closest to `2/3 * hidden_size * hidden_ratio`
if hidden_ratio is None:
hidden_ratio = 4
if intermediate_size is None:
intermediate_size = int(hidden_size * hidden_ratio * 2 / 3)
intermediate_size = 256 * ((intermediate_size + 256 - 1) // 256)
self.hidden_ratio = hidden_ratio
self.intermediate_size = intermediate_size
self.gate_proj = nn.Linear(self.hidden_size, self.intermediate_size * 2, bias=False)
self.down_proj = nn.Linear(self.intermediate_size, self.hidden_size, bias=False)
self.act_fn = ACT2FN[hidden_act]
def forward(self, x):
y = self.gate_proj(x)
gate, y = y.chunk(2, -1)
return swiglu_linear(gate, y, self.down_proj.weight, self.down_proj.bias)
class TransformerBlock(nn.Module):
def __init__(self, config: TransformerConfig, layer_idx: int):
super().__init__()
self.hidden_size = config.hidden_size
self.attn_norm = RMSNorm(hidden_size=config.hidden_size, eps=config.norm_eps)
self.attn = TransformerAttention(
config=config,
layer_idx=layer_idx
)
self.mlp_norm = RMSNorm(hidden_size=config.hidden_size, eps=config.norm_eps)
self.mlp = TransformerMLP(
hidden_size=config.hidden_size,
hidden_ratio=config.hidden_ratio,
intermediate_size=config.intermediate_size,
hidden_act=config.hidden_act
)
def forward(
self,
hidden_states: torch.Tensor,
attention_mask: Optional[torch.Tensor] = None,
past_key_values: Optional[Tuple[torch.Tensor]] = None,
output_attentions: Optional[bool] = False,
use_cache: Optional[bool] = False,
**kwargs,
) -> Tuple[torch.FloatTensor, Optional[Tuple[torch.FloatTensor, torch.FloatTensor]]]:
residual = hidden_states
hidden_states = self.attn_norm(hidden_states)
hidden_states, attentions, past_key_values = self.attn(
hidden_states=hidden_states,
attention_mask=attention_mask,
past_key_values=past_key_values,
use_cache=use_cache,
output_attentions=output_attentions
)
hidden_states, residual = self.mlp_norm(hidden_states, residual, True)
hidden_states = self.mlp(hidden_states)
hidden_states = residual + hidden_states
outputs = (hidden_states,)
if output_attentions:
outputs += (attentions,)
if use_cache:
outputs += (past_key_values,)
return outputs
class TransformerPreTrainedModel(PreTrainedModel):
config_class = TransformerConfig
supports_gradient_checkpointing = True
_no_split_modules = ['TransformerBlock']
def __init__(self, *inputs, **kwargs):
super().__init__(*inputs, **kwargs)
def _init_weights(
self,
module: nn.Module,
rescale_prenorm_residual: bool = True,
num_residuals_per_layer: int = 2,
):
if isinstance(module, (nn.Linear, nn.Conv1d)):
# Slightly different from the TF version which uses truncated_normal for initialization
# cf https://github.com/pytorch/pytorch/pull/5617
nn.init.normal_(module.weight, mean=0.0, std=self.config.initializer_range)
if module.bias is not None:
nn.init.zeros_(module.bias)
elif isinstance(module, nn.Embedding):
nn.init.normal_(module.weight, mean=0.0, std=self.config.initializer_range)
if module.padding_idx is not None:
module.weight.data[module.padding_idx].zero_()
if rescale_prenorm_residual:
# Reinitialize selected weights subject to the OpenAI GPT-2 Paper Scheme:
# > A modified initialization which accounts for the accumulation on the residual path with model depth. Scale
# > the weights of residual layers at initialization by a factor of 1/√N where N is the # of residual layers.
# > -- GPT-2 :: https://openai.com/blog/better-language-models/
#
# Reference (Megatron-LM): https://github.com/NVIDIA/Megatron-LM/blob/main/megatron/model/gpt_model.py
for name, p in module.named_parameters():
if name in ["o_proj.weight", "down_proj.weight"]:
# Special Scaled Initialization --> There are 2 Layer Norms per Transformer Block
# Following Pytorch init, except scale by 1/sqrt(2 * n_layer)
# We need to reinit p since this code could be called multiple times
# Having just p *= scale would repeatedly scale it down
with torch.no_grad():
p /= math.sqrt(num_residuals_per_layer * self.config.num_hidden_layers)
class TransformerModel(TransformerPreTrainedModel):
def __init__(self, config: TransformerConfig):
super().__init__(config)
self.padding_idx = config.pad_token_id
self.vocab_size = config.vocab_size
self.embeddings = nn.Embedding(config.vocab_size, config.hidden_size, self.padding_idx)
self.layers = nn.ModuleList([TransformerBlock(config, layer_idx) for layer_idx in range(config.num_hidden_layers)])
self.norm = RMSNorm(config.hidden_size, eps=config.norm_eps)
self.gradient_checkpointing = False
self.post_init()
def get_input_embeddings(self):
return self.embeddings
def set_input_embeddings(self, value):
self.embeddings = value
def forward(
self,
input_ids: Optional[torch.LongTensor] = None,
attention_mask: Optional[torch.Tensor] = None,
past_key_values: Optional[List[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None
) -> Union[Tuple, CausalLMOutputWithPast]:
if output_attentions:
warnings.warn(
"`TransformerModel` does not support output attention weights now, so `output_attentions` is set to `False`."
)
output_attentions = False
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
use_cache = use_cache if use_cache is not None else (self.config.use_cache if not self.training else False)
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
# retrieve input_ids and inputs_embeds
if input_ids is not None and inputs_embeds is not None:
raise ValueError("You cannot specify both input_ids and inputs_embeds at the same time")
elif input_ids is None and inputs_embeds is None:
raise ValueError("You have to specify either input_ids or inputs_embeds")
if use_cache:
use_legacy_cache = not isinstance(past_key_values, Cache)
if use_legacy_cache:
past_key_values = DynamicCache.from_legacy_cache(past_key_values)
if inputs_embeds is None:
inputs_embeds = self.embeddings(input_ids)
# embed positions
hidden_states = inputs_embeds
if self.gradient_checkpointing and self.training:
if use_cache:
logger.warning_once(
"`use_cache=True` is incompatible with gradient checkpointing. Setting `use_cache=False`..."
)
use_cache = False
all_hidden_states = () if output_hidden_states else None
all_attns = () if output_attentions else None
next_decoder_cache = None
for layer in self.layers:
if output_hidden_states:
all_hidden_states += (hidden_states,)
if self.gradient_checkpointing and self.training:
layer_outputs = self._gradient_checkpointing_func(
layer.__call__,
hidden_states,
attention_mask,
past_key_values,
output_attentions,
use_cache
)
else:
layer_outputs = layer(
hidden_states,
attention_mask=attention_mask,
past_key_values=past_key_values,
output_attentions=output_attentions,
use_cache=use_cache
)
hidden_states = layer_outputs[0]
if use_cache:
next_decoder_cache = layer_outputs[2 if output_attentions else 1]
if output_attentions:
all_attns += (layer_outputs[1],)
hidden_states = self.norm(hidden_states)
# add hidden states from the last decoder layer
if output_hidden_states:
all_hidden_states += (hidden_states,)
next_cache = None
if use_cache:
next_cache = next_decoder_cache.to_legacy_cache() if use_legacy_cache else next_decoder_cache
if not return_dict:
return tuple(v for v in [hidden_states, next_cache, all_hidden_states, all_attns] if v is not None)
return BaseModelOutputWithPast(
last_hidden_state=hidden_states,
past_key_values=next_cache,
hidden_states=all_hidden_states,
attentions=all_attns
)
class TransformerForCausalLM(TransformerPreTrainedModel):
_tied_weights_keys = ["lm_head.weight"]
def __init__(self, config):
super().__init__(config)
self.model = TransformerModel(config)
self.vocab_size = config.vocab_size
self.lm_head = nn.Linear(config.hidden_size, config.vocab_size, bias=False)
# Initialize weights and apply final processing
self.post_init()
def get_input_embeddings(self):
return self.model.embeddings
def set_input_embeddings(self, value):
self.model.embeddings = value
def get_output_embeddings(self):
return self.lm_head
def set_output_embeddings(self, new_embeddings):
self.lm_head = new_embeddings
def set_decoder(self, decoder):
self.model = decoder
def get_decoder(self):
return self.model
def prepare_inputs_for_generation(
self,
input_ids: torch.LongTensor = None,
past_key_values: Optional[torch.Tensor] = None,
attention_mask: Optional[torch.Tensor] = None,
inputs_embeds: Optional[torch.Tensor] = None,
**kwargs
):
# only last token for `inputs_ids` if the `past_key_values` is passed along.
if past_key_values is not None:
input_ids = input_ids[:, -1:]
# if `inputs_embeds` are passed, we only want to use them in the 1st generation step
if inputs_embeds is not None and past_key_values is None:
model_inputs = {'inputs_embeds': inputs_embeds}
else:
# The `contiguous()` here is necessary to have a static stride during decoding. torchdynamo otherwise
# recompiles graphs as the stride of the inputs is a guard.
# Ref: https://github.com/huggingface/transformers/pull/29114
# TODO: use `next_tokens` directly instead.
model_inputs = {'input_ids': input_ids.contiguous()}
model_inputs.update({
'past_key_values': past_key_values,
'use_cache': kwargs.get('use_cache'),
'attention_mask': attention_mask,
})
return model_inputs
def forward(
self,
input_ids: torch.LongTensor = None,
attention_mask: Optional[torch.Tensor] = None,
past_key_values: Optional[List[torch.FloatTensor]] = None,
inputs_embeds: Optional[torch.FloatTensor] = None,
labels: Optional[torch.LongTensor] = None,
use_cache: Optional[bool] = None,
output_attentions: Optional[bool] = None,
output_hidden_states: Optional[bool] = None,
return_dict: Optional[bool] = None,
) -> Union[Tuple, CausalLMOutputWithPast]:
output_attentions = output_attentions if output_attentions is not None else self.config.output_attentions
output_hidden_states = (
output_hidden_states if output_hidden_states is not None else self.config.output_hidden_states
)
return_dict = return_dict if return_dict is not None else self.config.use_return_dict
outputs = self.model(
input_ids=input_ids,
attention_mask=attention_mask,
past_key_values=past_key_values,
inputs_embeds=inputs_embeds,
use_cache=use_cache,
output_attentions=output_attentions,
output_hidden_states=output_hidden_states,
return_dict=return_dict
)
hidden_states = outputs[0]
logits = self.lm_head(hidden_states)
loss = None
if labels is not None:
if self.config.fuse_cross_entropy:
loss_fct = FusedCrossEntropyLoss(inplace_backward=True)
else:
loss_fct = nn.CrossEntropyLoss()
# Enable model parallelism
labels = labels.to(logits.device)
labels = torch.cat((labels[..., 1:], torch.full_like(labels[:, :1], loss_fct.ignore_index)), 1)
loss = loss_fct(logits.view(-1, self.config.vocab_size), labels.view(-1))
if not return_dict:
output = (logits,) + outputs[1:]
return (loss,) + output if loss is not None else output
return CausalLMOutputWithPast(
loss=loss,
logits=logits,
past_key_values=outputs.past_key_values,
hidden_states=outputs.hidden_states,
attentions=outputs.attentions,
)