File size: 4,042 Bytes
ba84330 14870ca ba84330 14870ca ba84330 7ab7042 ba84330 7ab7042 14870ca 7ab7042 14870ca ba84330 14870ca ba84330 7ab7042 14870ca ba84330 14870ca ba84330 7ab7042 ba84330 7ab7042 ba84330 7ab7042 ba84330 14870ca 7ab7042 ba84330 7ab7042 ba84330 8667424 |
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 |
"""GPT Blocks used for the GPT Model."""
from typing import Any, Dict, Optional, Tuple
import torch
import torch.nn as nn
from .attention import ATTN_CLASS_REGISTRY
from .ffn import FFN_CLASS_REGISTRY, build_ffn
from .norm import NORM_CLASS_REGISTRY
try:
from flash_attn.bert_padding import unpad_input, pad_input
except:
(unpad_input, pad_input) = (None, None)
attn_config_defaults: Dict = {'attn_type': 'multihead_attention', 'attn_pdrop': 0.0, 'attn_impl': 'triton', 'qk_ln': False, 'qk_gn': False, 'clip_qkv': None, 'softmax_scale': None, 'prefix_lm': False, 'attn_uses_sequence_id': False, 'sliding_window_size': -1, 'alibi': False, 'alibi_bias_max': 8, 'rope': False, 'rope_theta': 10000, 'rope_impl': 'dail', 'rope_dail_config': {'type': 'original', 'pos_idx_in_fp32': True, 'xpos_scale_base': 512}, 'rope_hf_config': {'type': 'no_scaling', 'factor': 1.0}}
class MPTBlock(nn.Module):
def __init__(self, d_model: int, n_heads: int, expansion_ratio: int, attn_config: Optional[Dict]=None, ffn_config: Optional[Dict]=None, resid_pdrop: float=0.0, norm_type: str='low_precision_layernorm', fc_type: str='torch', device: Optional[str]=None, no_bias: bool=False, use_pad_tok_in_ffn: bool=True, **kwargs: Any):
if attn_config is None:
attn_config = attn_config_defaults
if ffn_config is None:
ffn_config = {'ffn_type': 'mptmlp'}
del kwargs
super().__init__()
norm_class = NORM_CLASS_REGISTRY[norm_type.lower()]
assert isinstance(attn_config['attn_type'], str)
attn_class = ATTN_CLASS_REGISTRY[attn_config['attn_type']]
args_to_exclude_in_attn_class = {'attn_type', 'prefix_lm', 'alibi', 'attn_uses_sequence_id', 'alibi_bias_max', 'rope', 'rope_theta', 'rope_impl', 'rope_dail_config', 'rope_hf_config'}
attn_config_subset_for_attn_class = {k: v for (k, v) in attn_config.items() if k not in args_to_exclude_in_attn_class}
self.norm_1 = norm_class(d_model, device=device)
self.attn = attn_class(d_model=d_model, n_heads=n_heads, fc_type=fc_type, device=device, **attn_config_subset_for_attn_class, bias=not no_bias)
self.norm_2 = None
if not getattr(FFN_CLASS_REGISTRY[ffn_config['ffn_type']], '_has_norm', False):
self.norm_2 = norm_class(d_model, device=device)
self.ffn = build_ffn(d_model=d_model, expansion_ratio=expansion_ratio, device=device, bias=not no_bias, **ffn_config)
self.resid_attn_dropout = nn.Dropout(resid_pdrop)
self.resid_ffn_dropout = nn.Dropout(resid_pdrop)
self.use_pad_tok_in_ffn = use_pad_tok_in_ffn
def forward(self, x: torch.Tensor, past_key_value: Optional[Tuple[torch.Tensor, torch.Tensor]]=None, attn_bias: Optional[torch.Tensor]=None, rotary_emb_w_meta_info: Optional[Dict]=None, attention_mask: Optional[torch.ByteTensor]=None, is_causal: bool=True, output_attentions: bool=False, alibi_slopes: Optional[torch.Tensor]=None, flash_attn_padding_info: Optional[dict[str, torch.Tensor]]=None) -> Tuple[torch.Tensor, Optional[torch.Tensor], Optional[Tuple[torch.Tensor, torch.Tensor]]]:
a = self.norm_1(x)
(b, attn_weights, past_key_value) = self.attn(a, past_key_value=past_key_value, attn_bias=attn_bias, rotary_emb_w_meta_info=rotary_emb_w_meta_info, attention_mask=attention_mask, is_causal=is_causal, needs_weights=output_attentions, alibi_slopes=alibi_slopes, flash_attn_padding_info=flash_attn_padding_info)
x = x + self.resid_attn_dropout(b)
m = x
if self.norm_2 is not None:
m = self.norm_2(x)
(batch_size, seq_len) = m.size()[:2]
indices = None
if not self.use_pad_tok_in_ffn:
assert unpad_input is not None
(m, indices, _, _) = unpad_input(m, attention_mask)
n = self.ffn(m)
if not self.use_pad_tok_in_ffn:
assert pad_input is not None
n = pad_input(n, indices, batch_size, seq_len)
x = x + self.resid_ffn_dropout(n)
return (x, attn_weights, past_key_value) |