Minimind/model/model.py

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import math
import struct
import inspect
import time
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from .LMConfig import LMConfig
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from typing import Any, Optional, Tuple, List, Union
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import numpy as np
import torch
import torch.nn.functional as F
from torch import nn
from transformers import PreTrainedModel
from transformers.modeling_outputs import CausalLMOutputWithPast
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from torch import nn, einsum
from einops import rearrange, repeat
def exists(val):
return val is not None
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# RMSNorm 类定义了一个用于归一化输入张量的模块。
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class RMSNorm(torch.nn.Module):
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def __init__(self, dim: int, eps: float = 1e-6):
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super().__init__()
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self.eps = eps
self.weight = nn.Parameter(torch.ones(dim))
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def _norm(self, x):
return x * torch.rsqrt(x.pow(2).mean(-1, keepdim=True) + self.eps)
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def forward(self, x):
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return self.weight * self._norm(x.float()).type_as(x)
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# precompute_pos_cis 函数用于预计算位置编码。
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def precompute_pos_cis(dim: int, end: int = int(32 * 1024), theta: float = 1e6):
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freqs = 1.0 / (theta ** (torch.arange(0, dim, 2)[: (dim // 2)].float() / dim))
t = torch.arange(end, device=freqs.device) # type: ignore
freqs = torch.outer(t, freqs).float() # type: ignore
pos_cis = torch.polar(torch.ones_like(freqs), freqs) # complex64
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return pos_cis
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# apply_rotary_emb 函数用于应用旋转位置编码。
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def apply_rotary_emb(xq, xk, pos_cis):
def unite_shape(pos_cis, x):
ndim = x.ndim
assert 0 <= 1 < ndim
assert pos_cis.shape == (x.shape[1], x.shape[-1])
shape = [d if i == 1 or i == ndim - 1 else 1 for i, d in enumerate(x.shape)]
return pos_cis.view(*shape)
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xq_ = torch.view_as_complex(xq.float().reshape(*xq.shape[:-1], -1, 2))
xk_ = torch.view_as_complex(xk.float().reshape(*xk.shape[:-1], -1, 2))
pos_cis = unite_shape(pos_cis, xq_)
xq_out = torch.view_as_real(xq_ * pos_cis).flatten(3)
xk_out = torch.view_as_real(xk_ * pos_cis).flatten(3)
return xq_out.type_as(xq), xk_out.type_as(xk)
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# repeat_kv 函数用于重复键值对。
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def repeat_kv(x: torch.Tensor, n_rep: int) -> torch.Tensor:
"""torch.repeat_interleave(x, dim=2, repeats=n_rep)"""
bs, slen, n_kv_heads, head_dim = x.shape
if n_rep == 1:
return x
return (
x[:, :, :, None, :]
.expand(bs, slen, n_kv_heads, n_rep, head_dim)
.reshape(bs, slen, n_kv_heads * n_rep, head_dim)
)
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class Attention(nn.Module):
def __init__(self, args: LMConfig):
super().__init__()
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self.n_kv_heads = args.n_heads if args.n_kv_heads is None else args.n_kv_heads
assert args.n_heads % self.n_kv_heads == 0
self.n_local_heads = args.n_heads
self.n_local_kv_heads = self.n_kv_heads
self.n_rep = self.n_local_heads // self.n_local_kv_heads
self.head_dim = args.dim // args.n_heads
self.wq = nn.Linear(args.dim, args.n_heads * self.head_dim, bias=False)
self.wk = nn.Linear(args.dim, self.n_kv_heads * self.head_dim, bias=False)
self.wv = nn.Linear(args.dim, self.n_kv_heads * self.head_dim, bias=False)
self.wo = nn.Linear(args.n_heads * self.head_dim, args.dim, bias=False)
self.attn_dropout = nn.Dropout(args.dropout)
self.resid_dropout = nn.Dropout(args.dropout)
self.dropout = args.dropout
self.flash = hasattr(torch.nn.functional, 'scaled_dot_product_attention') and args.flash_attn
# print("WARNING: using slow attention. Flash Attention requires PyTorch >= 2.0")
mask = torch.full((1, 1, args.max_seq_len, args.max_seq_len), float("-inf"))
mask = torch.triu(mask, diagonal=1)
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self.register_buffer("mask", mask, persistent=False)
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def forward(self,
x: torch.Tensor,
pos_cis: torch.Tensor,
past_key_value: Optional[Tuple[torch.Tensor, torch.Tensor]] = None,
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use_cache=False,
db_value=None):
bsz, seq_len, _ = x.shape #bsz: 批量大小, seq_len: 序列长度, _: 隐藏维度
xq, xk, xv = self.wq(x), self.wk(x), self.wv(x) #将输入张量x分别通过线性层wq, wk, wv进行变换得到查询、键和值。
xq = xq.view(bsz, seq_len, self.n_local_heads, self.head_dim) #将变换后的张量xq重塑为形状为(bsz, seq_len, n_local_heads, head_dim)的形状。
xk = xk.view(bsz, seq_len, self.n_local_kv_heads, self.head_dim) #将变换后的张量xk重塑为形状为(bsz, seq_len, n_local_kv_heads, head_dim)的形状。
xv = xv.view(bsz, seq_len, self.n_local_kv_heads, self.head_dim) #将变换后的张量xv重塑为形状为(bsz, seq_len, n_local_kv_heads, head_dim)的形状。
# 应用旋转位置编码
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xq, xk = apply_rotary_emb(xq, xk, pos_cis)
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# kv_cache实现
if past_key_value is not None:
xk = torch.cat([past_key_value[0], xk], dim=1)
xv = torch.cat([past_key_value[1], xv], dim=1)
past_kv = (xk, xv) if use_cache else None
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# 重复键值对
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xq, xk, xv = (
xq.transpose(1, 2),
repeat_kv(xk, self.n_rep).transpose(1, 2),
repeat_kv(xv, self.n_rep).transpose(1, 2)
)
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# 如果提供了db_value根据头的数量调整它的形状并与xv合并
if db_value is not None:
# 确保db_value的形状与xv兼容假设db_value形状为[B, N, H, D]
if db_value.ndim == 4: # [B, N, H, D]
db_value = db_value.transpose(1, 2) # -> [B, H, N, D]
# 检查是否需要调整D维度
if db_value.shape[-1] != xv.shape[-1]:
# 如果db_value的维度与xv不同可以添加一个投影层
# 或者在这里使用简单的调整方法
# 这里我们简单地通过均值池化或重复来调整维度
if db_value.shape[-1] > xv.shape[-1]:
# 降维
factor = db_value.shape[-1] // xv.shape[-1]
db_value = db_value.view(bsz, self.n_local_heads, seq_len, factor, xv.shape[-1])
db_value = db_value.mean(dim=3)
else:
# 升维
factor = xv.shape[-1] // db_value.shape[-1]
db_value = db_value.unsqueeze(-1).repeat(1, 1, 1, 1, factor)
db_value = db_value.view(bsz, self.n_local_heads, seq_len, xv.shape[-1])
# 将db_value与xv相加或融合
# 这里我们简单地将它们相加,但你也可以使用其他融合方法
xv = xv + db_value
# 使用Flash Attention
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if self.flash and seq_len != 1:
dropout_p = self.dropout if self.training else 0.0
output = F.scaled_dot_product_attention(
xq, xk, xv,
attn_mask=None,
dropout_p=dropout_p,
is_causal=True
)
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else:
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scores = (xq @ xk.transpose(-2, -1)) / math.sqrt(self.head_dim)
scores += self.mask[:, :, :seq_len, :seq_len]
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scores = F.softmax(scores.float(), dim=-1).type_as(xq)
scores = self.attn_dropout(scores)
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output = scores @ xv
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output = output.transpose(1, 2).reshape(bsz, seq_len, -1)
output = self.resid_dropout(self.wo(output))
return output, past_kv
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class CrossAttention(nn.Module):
def __init__(
self,
config
):
super().__init__()
self.config = config
self.num_heads = 8
self.head_dim = self.config.dim // self.num_heads
self.to_q = nn.Linear(self.config.dim, self.config.dim, bias=False)
self.to_k = nn.Linear(self.config.dim, self.config.dim, bias=False)
self.to_v = nn.Linear(self.config.dim, self.config.dim, bias=False)
self.to_out = nn.Linear(self.config.dim, self.config.dim, bias=False)
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def forward(self, x, db, context_mask=None, pos_emb=None):
batch_size = x.size(0)
# 分离多头
q = self.to_q(x).view(batch_size, -1, self.num_heads, self.head_dim).transpose(1, 2)
k = self.to_k(db).view(batch_size, -1, self.num_heads, self.head_dim).transpose(1, 2)
v = self.to_v(db).view(batch_size, -1, self.num_heads, self.head_dim).transpose(1, 2)
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if pos_emb is not None:
pos_emb = pos_emb.view(batch_size, -1, self.num_heads, self.head_dim).transpose(1, 2)
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q = q + pos_emb
k = k + pos_emb
v = v + pos_emb
attn_scores = torch.matmul(q, k.transpose(-2, -1)) / math.sqrt(self.head_dim)
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if context_mask is not None:
expanded_mask = context_mask.unsqueeze(1).expand(-1, self.num_heads, -1, -1)
attn_scores = attn_scores.masked_fill(expanded_mask == 0, -1e10)
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attn_weights = F.softmax(attn_scores, dim=-1)
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context = torch.matmul(attn_weights, v)
context = context.transpose(1, 2).contiguous().view(batch_size, -1, self.config.dim)
context = self.to_out(context)
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return context
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class FeedForward(nn.Module):
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def __init__(self, config: LMConfig):
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super().__init__()
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if config.hidden_dim is None:
hidden_dim = 4 * config.dim
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hidden_dim = int(2 * hidden_dim / 3)
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config.hidden_dim = config.multiple_of * ((hidden_dim + config.multiple_of - 1) // config.multiple_of)
self.w1 = nn.Linear(config.dim, config.hidden_dim, bias=False)
self.w2 = nn.Linear(config.hidden_dim, config.dim, bias=False)
self.w3 = nn.Linear(config.dim, config.hidden_dim, bias=False)
self.dropout = nn.Dropout(config.dropout)
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def forward(self, x):
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return self.dropout(self.w2(F.silu(self.w1(x)) * self.w3(x)))
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class MoEGate(nn.Module):
def __init__(self, config: LMConfig):
super().__init__()
self.config = config
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self.top_k = config.num_experts_per_tok
self.n_routed_experts = config.n_routed_experts
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self.scoring_func = config.scoring_func
self.alpha = config.aux_loss_alpha
self.seq_aux = config.seq_aux
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self.norm_topk_prob = config.norm_topk_prob
self.gating_dim = config.dim
self.weight = nn.Parameter(torch.empty((self.n_routed_experts, self.gating_dim)))
self.reset_parameters()
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def reset_parameters(self) -> None:
import torch.nn.init as init
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init.kaiming_uniform_(self.weight, a=math.sqrt(5))
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def forward(self, hidden_states):
bsz, seq_len, h = hidden_states.shape
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hidden_states = hidden_states.view(-1, h)
logits = F.linear(hidden_states, self.weight, None)
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if self.scoring_func == 'softmax':
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scores = logits.softmax(dim=-1)
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else:
raise NotImplementedError(f'insupportable scoring function for MoE gating: {self.scoring_func}')
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topk_weight, topk_idx = torch.topk(scores, k=self.top_k, dim=-1, sorted=False)
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if self.top_k > 1 and self.norm_topk_prob:
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denominator = topk_weight.sum(dim=-1, keepdim=True) + 1e-20
topk_weight = topk_weight / denominator
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if self.training and self.alpha > 0.0:
scores_for_aux = scores
aux_topk = self.top_k
topk_idx_for_aux_loss = topk_idx.view(bsz, -1)
if self.seq_aux:
scores_for_seq_aux = scores_for_aux.view(bsz, seq_len, -1)
ce = torch.zeros(bsz, self.n_routed_experts, device=hidden_states.device)
ce.scatter_add_(1, topk_idx_for_aux_loss,
torch.ones(bsz, seq_len * aux_topk, device=hidden_states.device)).div_(
seq_len * aux_topk / self.n_routed_experts)
aux_loss = (ce * scores_for_seq_aux.mean(dim=1)).sum(dim=1).mean() * self.alpha
else:
mask_ce = F.one_hot(topk_idx_for_aux_loss.view(-1), num_classes=self.n_routed_experts)
ce = mask_ce.float().mean(0)
Pi = scores_for_aux.mean(0)
fi = ce * self.n_routed_experts
aux_loss = (Pi * fi).sum() * self.alpha
else:
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aux_loss = 0
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return topk_idx, topk_weight, aux_loss
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class MOEFeedForward(nn.Module):
def __init__(self, config: LMConfig):
super().__init__()
self.config = config
self.experts = nn.ModuleList([
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FeedForward(config)
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for _ in range(config.n_routed_experts)
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])
self.gate = MoEGate(config)
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if config.n_shared_experts is not None:
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self.shared_experts = FeedForward(config)
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def forward(self, x):
identity = x
orig_shape = x.shape
bsz, seq_len, _ = x.shape
# 使用门控机制选择专家
topk_idx, topk_weight, aux_loss = self.gate(x)
x = x.view(-1, x.shape[-1])
flat_topk_idx = topk_idx.view(-1)
if self.training:
x = x.repeat_interleave(self.config.num_experts_per_tok, dim=0)
y = torch.empty_like(x, dtype=torch.float16)
for i, expert in enumerate(self.experts):
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y[flat_topk_idx == i] = expert(x[flat_topk_idx == i]).to(y.dtype) # 确保类型一致
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y = (y.view(*topk_weight.shape, -1) * topk_weight.unsqueeze(-1)).sum(dim=1)
y = y.view(*orig_shape)
else:
y = self.moe_infer(x, flat_topk_idx, topk_weight.view(-1, 1)).view(*orig_shape)
if self.config.n_shared_experts is not None:
y = y + self.shared_experts(identity)
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self.aux_loss = aux_loss
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return y
@torch.no_grad()
def moe_infer(self, x, flat_expert_indices, flat_expert_weights):
expert_cache = torch.zeros_like(x)
idxs = flat_expert_indices.argsort()
tokens_per_expert = flat_expert_indices.bincount().cpu().numpy().cumsum(0)
token_idxs = idxs // self.config.num_experts_per_tok
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# 当tokens_per_expert = [6, 15, 20, 26]tokens_per_expert.shape[0]即为专家数量此时为4
# 且token_idxs = [3, 7, 19, 21, 24, 25, 4, 5, 6, 10, 11, 12...] 时
# 意味token_idxs[:6] -> [3, 7, 19, 21, 24, 25]这6个位置属于专家0处理的token每个token有可能被多个专家处理这取决于num_experts_per_tok
# 接下来9个位置token_idxs[6:15] -> [4, 5, 6, 10, 11, 12...]属于专家1处理的token...依此类推
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for i, end_idx in enumerate(tokens_per_expert):
start_idx = 0 if i == 0 else tokens_per_expert[i - 1]
if start_idx == end_idx:
continue
expert = self.experts[i]
exp_token_idx = token_idxs[start_idx:end_idx]
expert_tokens = x[exp_token_idx]
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expert_out = expert(expert_tokens).to(expert_cache.dtype)
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expert_out.mul_(flat_expert_weights[idxs[start_idx:end_idx]])
expert_cache.scatter_add_(0, exp_token_idx.view(-1, 1).repeat(1, x.shape[-1]), expert_out)
return expert_cache
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class MiniMindBlock(nn.Module):
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def __init__(self, layer_id: int, config: LMConfig):
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super().__init__()
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self.n_heads = config.n_heads
self.dim = config.dim
self.head_dim = config.dim // config.n_heads
self.attention = Attention(config)
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self.cross_att = CrossAttention(config)
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self.layer_id = layer_id
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self.attention_norm = RMSNorm(config.dim, eps=config.norm_eps)
self.ffn_norm = RMSNorm(config.dim, eps=config.norm_eps)
self.feed_forward = FeedForward(config) if not config.use_moe else MOEFeedForward(config)
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# 假设num_experts是已定义的总专家数量的平方根
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# 查询生成的参数
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# 创建查询生成模块
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# if weight_down_embed is not None:
# self.to_queries = nn.Sequential(
# nn.Linear(config.dim, self.dim_key * 2, bias=False),
# # nn.Unflatten(2, (2, self.n_heads, self.dim_key)) # 替代Rearrange
# )
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# # 超参数
# self.product_key_topk = min(16, self.num_keys) # 确保不超过num_keys
# self.num_experts_per_head_topk = 1 # 最终每个头选取的专家数
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def forward(self, x, db_value, pos_cis, past_key_value=None, use_cache=False):
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# import pdb;pdb.set_trace()
# db_value = None
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# # 如果有weight_down_embed使用Product Key机制
# if self.weight_down_embed is not None:
# # 1. 生成queries
# batch_size, seq_len, dim = x.shape
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# # collapse sequence dimension by averaging
# x_flat = x.mean(dim=1) # [batch_size, dim]
# queries = self.to_queries(x_flat) # [batch_size, 2*dim_key]
# queries = queries.reshape(batch_size, 2, self.dim_key) # [batch_size, 2, dim_key]
# queries = queries.permute(1, 0, 2) # [2, batch_size, dim_key]
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# # 2. 计算queries与keys的相似度
# sim = torch.einsum('p b d, k p d -> p b k', queries, self.keys)
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# # 3. 在两个子空间分别做top-k
# scores_and_indices = [sim[p].topk(self.product_key_topk, dim=-1) for p in range(2)]
# scores_x, scores_y = scores_and_indices[0][0], scores_and_indices[1][0]
# indices_x, indices_y = scores_and_indices[0][1], scores_and_indices[1][1]
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# # 4. 组合两个子空间的分数和索引
# all_scores = scores_x.unsqueeze(-1) + scores_y.unsqueeze(-2)
# all_scores = all_scores.view(*all_scores.shape[:-2], -1)
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# all_indices = (indices_x.unsqueeze(-1) * self.num_keys) + indices_y.unsqueeze(-2)
# all_indices = all_indices.view(*all_indices.shape[:-2], -1)
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# # 5. 最终top-k选择
# scores, pk_indices = all_scores.topk(self.num_experts_per_head_topk, dim=-1)
# indices = all_indices.gather(-1, pk_indices)
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# # 6. 从embedding中获取专家值
# # 从embedding中获取值
# flat_indices = indices.view(-1) # 将索引展平为一维张量
# db_values = self.weight_down_embed(flat_indices)
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# # 重塑回原始形状
# db_value = db_values.view(batch_size, -1, dim)
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# 注意力计算
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h_attn, past_kv = self.attention(
self.attention_norm(x),
pos_cis,
past_key_value=past_key_value,
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use_cache=use_cache,
db_value=db_value
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)
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h_attn = self.cross_att(h_attn, db_value)
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# 残差连接
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h = x + h_attn
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# 前馈神经网络
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out = h + self.feed_forward(self.ffn_norm(h))
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return out, past_kv
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class ExtractDB(nn.Module):
def __init__(self,params):
# 修改专家数量和知识维度,确保能开方
super().__init__()
self.batch_size = None
self.dim = params.dim
self.dim_key = self.dim // 2
self.num_experts = 10 * 10 # 100专家确保是完全平方数
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# 将knowledge_dim设置为与head_dim相同以便在attention中直接使用
self.head_dim = params.dim // params.n_heads
self.knowledge_dim = 8*params.dim
# 使用register_buffer代替nn.Parameter避免梯度问题
self.register_buffer('weight_down_embed', torch.randn(self.num_experts, self.knowledge_dim) * 0.02)
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self.num_keys = int(math.sqrt(self.num_experts)) if self.num_experts > 0 else 0
self.product_key_topk = min(16, self.num_keys)
self.keys = nn.Parameter(torch.randn(self.num_keys, 2, self.dim_key) * 0.02)
self.num_experts_per_head_topk = 1
self.to_queries = nn.Sequential(
nn.Linear(params.dim, self.dim_key * 2, bias=False),
)
def q_to_k(self,x):
# 1. 生成queries
self.batch_size, seq_len, dim = x.shape
# collapse sequence dimension by averaging
x_flat = x.mean(dim=1) # [batch_size, dim]
queries = self.to_queries(x_flat) # [batch_size, 2*dim_key]
queries = queries.reshape(self.batch_size, 2, self.dim_key) # [batch_size, 2, dim_key]
queries = queries.permute(1, 0, 2) # [2, batch_size, dim_key]
# 2. 计算queries与keys的相似度
sim = torch.einsum('p b d, k p d -> p b k', queries, self.keys)
# 3. 在两个子空间分别做top-k
scores_and_indices = [sim[p].topk(self.product_key_topk, dim=-1) for p in range(2)]
scores_x, scores_y = scores_and_indices[0][0], scores_and_indices[1][0]
indices_x, indices_y = scores_and_indices[0][1], scores_and_indices[1][1]
# 4. 组合两个子空间的分数和索引
all_scores = scores_x.unsqueeze(-1) + scores_y.unsqueeze(-2)
all_scores = all_scores.view(*all_scores.shape[:-2], -1)
all_indices = (indices_x.unsqueeze(-1) * self.num_keys) + indices_y.unsqueeze(-2)
all_indices = all_indices.view(*all_indices.shape[:-2], -1)
# 5. 最终top-k选择
scores, pk_indices = all_scores.topk(self.num_experts_per_head_topk, dim=-1)
indices = all_indices.gather(-1, pk_indices)
flat_indices = indices.view(-1)
return flat_indices
def get_data(self, index):
# 直接从GPU获取embedding
db_values = self.weight_down_embed[index]
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db_value = db_values.view(self.batch_size, -1, self.dim)
return db_value
@torch.no_grad()
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def updata_value(self, k, v):
# 直接更新buffer上的值 (不需要梯度)
v_reshaped = v.view(v.size(0), -1)
# 确保数据类型匹配
v_reshaped = v_reshaped.to(dtype=self.weight_down_embed.dtype)
self.weight_down_embed[k] = v_reshaped
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class MiniMindLM(PreTrainedModel):
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config_class = LMConfig
def __init__(self, params: LMConfig = None):
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self.params = params or LMConfig()
super().__init__(self.params)
self.vocab_size, self.n_layers = params.vocab_size, params.n_layers
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self.tok_embeddings = nn.Embedding(params.vocab_size, params.dim)
self.dropout = nn.Dropout(params.dropout)
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# 移除旧的weight_down_embed声明
self.extract_db = ExtractDB(self.params)
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# 将self.weight_down_embed传递给每个MiniMindBlock
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self.layers = nn.ModuleList([MiniMindBlock(l, params) for l in range(self.n_layers)])
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self.norm = RMSNorm(params.dim, eps=params.norm_eps)
self.output = nn.Linear(params.dim, params.vocab_size, bias=False)
self.tok_embeddings.weight = self.output.weight
# Calculate input dimension
input_dim = (self.params.max_seq_len-1)*self.params.n_layers
# Use a bottleneck architecture to reduce parameters
bottleneck_dim = 256 # Significantly smaller bottleneck dimension
# Factorized shared downsampling using two smaller convolutions
self.shared_downsample = nn.Sequential(
# First reduce input dimension to bottleneck
nn.Conv1d(input_dim, bottleneck_dim, kernel_size=1, padding='same'),
nn.ReLU(), # Non-linearity to improve representation capacity
# Then expand to target dimension
nn.Conv1d(bottleneck_dim, 128*8, kernel_size=1, padding='same')
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)
# Specific layers for v path
self.downsample_v_specific = nn.Sequential(
nn.Conv1d(128*8, 128, kernel_size=1, padding='same'),
nn.Conv1d(128, 8, kernel_size=1, padding='same')
)
# Specific layers for q path
self.downsample_q_specific = nn.Sequential(
nn.Conv1d(128*8, 512, kernel_size=1, padding='same')
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)
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self.register_buffer("pos_cis",
precompute_pos_cis(dim=params.dim // params.n_heads, theta=params.rope_theta),
persistent=False)
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self.OUT = CausalLMOutputWithPast()
self.params = params
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def forward(self,
input_ids: Optional[torch.Tensor] = None,
past_key_values: Optional[List[Tuple[torch.Tensor, torch.Tensor]]] = None,
use_cache: bool = False,
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logits_to_keep: Union[int, torch.Tensor] = 0,
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**args):
past_key_values = past_key_values or [None] * len(self.layers)
start_pos = args.get('start_pos', 0)
h = self.dropout(self.tok_embeddings(input_ids))
pos_cis = self.pos_cis[start_pos:start_pos + input_ids.size(1)]
past_kvs = []
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h_list = []
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for l, layer in enumerate(self.layers):
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# 禁用数据库模式,使用固定值替代数据库查询
if self.params.disable_db:
# 创建一个形状为[batch_size, n_layers, dim]的tensor所有元素值为1e-4
batch_size = h.size(0)
db_value = torch.full((batch_size, self.n_layers, self.params.dim), 1e-4,
dtype=h.dtype, device=h.device)
else:
# 正常模式,使用数据库查询
index = self.extract_db.q_to_k(h)
db_value = self.extract_db.get_data(index)
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h, past_kv = layer(
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h, db_value, pos_cis,
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past_key_value=past_key_values[l],
use_cache=use_cache
)
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past_kvs.append(past_kv)
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h_list.append(h.unsqueeze(0))
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h_tensor = torch.cat(h_list, dim=0).permute(1, 0, 2, 3)
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# 只在非禁用数据库模式下执行数据库更新逻辑
if not self.params.disable_db:
# 使用detach()分离计算图,避免多次反向传播
h_tensor_detached = h_tensor.detach()
h_tensor_detached = h_tensor_detached.reshape(h_tensor_detached.shape[0], -1, self.params.dim)
# 数据库更新逻辑与主计算图分离
with torch.no_grad():
# Compute shared downsampling layer once
shared_features = self.shared_downsample(h_tensor_detached)
z_v = self.downsample_v_specific(shared_features)
z_q = self.downsample_q_specific(shared_features)
z_k = self.extract_db.q_to_k(z_q)
self.extract_db.updata_value(z_k, z_v)
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slice_indices = slice(-logits_to_keep, None) if isinstance(logits_to_keep, int) else logits_to_keep
logits = self.output(self.norm(h)[:, slice_indices, :])
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aux_loss = sum(l.feed_forward.aux_loss for l in self.layers if isinstance(l.feed_forward, MOEFeedForward))
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self.OUT.__setitem__('last_hidden_state', h)
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self.OUT.__setitem__('logits', logits)
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self.OUT.__setitem__('aux_loss', aux_loss)
self.OUT.__setitem__('past_key_values', past_kvs)
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return self.OUT
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@torch.inference_mode()
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def generate(self, input_ids, eos_token_id=2, max_new_tokens=1024, temperature=0.75, top_p=0.90,
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stream=False, rp=1., use_cache=True, pad_token_id=0, num_return_sequences=1, **args):
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# 流式生成
if stream:
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return self._stream(input_ids, eos_token_id, max_new_tokens, temperature, top_p, rp, use_cache, **args)
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# 直接生成
generated = []
for i in range(input_ids.size(0)):
non_pad = input_ids[i][input_ids[i] != pad_token_id].unsqueeze(0)
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for _ in range(num_return_sequences):
out = self._stream(non_pad, eos_token_id, max_new_tokens, temperature, top_p, rp, use_cache, **args)
tokens_list = [tokens[:, -1:] for tokens in out]
gen = torch.cat(tokens_list, dim=-1) if tokens_list else non_pad
full_sequence = torch.cat([non_pad, gen], dim=-1)
generated.append(full_sequence)
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max_length = max(seq.size(1) for seq in generated)
generated = [
torch.cat(
[seq, torch.full((1, max_length - seq.size(1)), pad_token_id, dtype=seq.dtype, device=seq.device)],
dim=-1)
for seq in generated
]
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output = torch.cat(generated, dim=0)
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res = output.view(input_ids.size(0) * num_return_sequences, -1)
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return res
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def _stream(self, input_ids, eos_token_id, max_new_tokens, temperature, top_p, rp, use_cache, **args):
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start, first_seq, past_kvs = input_ids.shape[1], True, None
while input_ids.shape[1] < max_new_tokens - 1:
if first_seq or not use_cache:
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out, first_seq = self(input_ids, past_key_values=past_kvs, use_cache=use_cache, **args), False
else:
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out = self(input_ids[:, -1:], past_key_values=past_kvs, use_cache=use_cache,
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start_pos=input_ids.shape[1] - 1, **args)
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logits, past_kvs = out.logits[:, -1, :], out.past_key_values
logits[:, list(set(input_ids.tolist()[0]))] /= rp
logits /= (temperature + 1e-9)
if top_p is not None and top_p < 1.0:
sorted_logits, sorted_indices = torch.sort(logits, descending=True, dim=-1)
sorted_probs = F.softmax(sorted_logits, dim=-1)
cumulative_probs = torch.cumsum(sorted_probs, dim=-1)
sorted_indices_to_remove = cumulative_probs > top_p
sorted_indices_to_remove[:, 1:] = sorted_indices_to_remove[:, :-1].clone()
sorted_indices_to_remove[:, 0] = False
indices_to_remove = sorted_indices_to_remove.scatter(1, sorted_indices, sorted_indices_to_remove)
logits[indices_to_remove] = -float('Inf')
input_ids_next = torch.multinomial(F.softmax(logits, dim=-1), num_samples=1)
input_ids = torch.cat((input_ids, input_ids_next), dim=1)
yield input_ids[:, start:]
if input_ids_next.item() == eos_token_id:
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break