从零训练LLM_sft微调

1. 准备训练数据

image-20250425111417618

2. 准备模型

2.1 准备Tokenizer模型

这里测试,先用自己训练的

image-20250425143757883

正式,建议使用第三方的

image-20250425143743936

3. 准备训练脚本

跟预训练不同的,有3点

  • init_model模型时,需要加载预训练好的模型

    def init_model(lm_config):
        tokenizer = AutoTokenizer.from_pretrained('/root/model/tokenizer')
        model = MiniMindLM(lm_config)
        moe_path = '_moe' if lm_config.use_moe else ''
        ckp = f'./out/pretrain_{lm_config.dim}{moe_path}.pth'
        state_dict = torch.load(ckp, map_location=args.device)
        model.load_state_dict(state_dict, strict=False)
        Logger(f'LLM总参数量:{sum(p.numel() for p in model.parameters() if p.requires_grad) / 1e6:.3f} 百万')
        model = model.to(args.device)
        return model, tokenizer
    
  • 数据集加载方式的不同

    train_ds = SFTDataset(args.data_path, tokenizer, max_length=lm_config.max_seq_len)
    
  • 模型保存路径不同

    ckp = f'{args.save_dir}/full_sft_{lm_config.dim}{moe_path}.pth'
    

Train_SFT.py

warnings.filterwarnings('ignore')


def Logger(content):
    if not ddp or dist.get_rank() == 0:
        print(content)


def get_lr(current_step, total_steps, lr):
    return lr / 10 + 0.5 * lr * (1 + math.cos(math.pi * current_step / total_steps))


def train_epoch(epoch, wandb):
    loss_fct = nn.CrossEntropyLoss(reduction='none')
    start_time = time.time()
    for step, (X, Y, loss_mask) in enumerate(train_loader):
        X = X.to(args.device)
        Y = Y.to(args.device)
        loss_mask = loss_mask.to(args.device)
        lr = get_lr(epoch * iter_per_epoch + step, args.epochs * iter_per_epoch, args.learning_rate)
        for param_group in optimizer.param_groups:
            param_group['lr'] = lr

        with ctx:
            res = model(X)
            loss = loss_fct(
                res.logits.view(-1, res.logits.size(-1)),
                Y.view(-1)
            ).view(Y.size())

            loss = (loss * loss_mask).sum() / loss_mask.sum()
            loss += res.aux_loss
            loss = loss / args.accumulation_steps

        scaler.scale(loss).backward()

        if (step + 1) % args.accumulation_steps == 0:
            scaler.unscale_(optimizer)
            torch.nn.utils.clip_grad_norm_(model.parameters(), args.grad_clip)

            scaler.step(optimizer)
            scaler.update()

            optimizer.zero_grad(set_to_none=True)

        if step % args.log_interval == 0:
            spend_time = time.time() - start_time
            Logger(
                'Epoch:[{}/{}]({}/{}) loss:{:.3f} lr:{:.12f} epoch_Time:{}min:'.format(
                    epoch + 1,
                    args.epochs,
                    step,
                    iter_per_epoch,
                    loss.item(),
                    optimizer.param_groups[-1]['lr'],
                    spend_time / (step + 1) * iter_per_epoch // 60 - spend_time // 60))

            if (wandb is not None) and (not ddp or dist.get_rank() == 0):
                wandb.log({"loss": loss,
                           "lr": optimizer.param_groups[-1]['lr'],
                           "epoch_Time": spend_time / (step + 1) * iter_per_epoch // 60 - spend_time // 60})

        if (step + 1) % args.save_interval == 0 and (not ddp or dist.get_rank() == 0):
            model.eval()
            moe_path = '_moe' if lm_config.use_moe else ''
            ckp = f'{args.save_dir}/full_sft_{lm_config.dim}{moe_path}.pth'

            if isinstance(model, torch.nn.parallel.DistributedDataParallel):
                state_dict = model.module.state_dict()
            else:
                state_dict = model.state_dict()

            torch.save(state_dict, ckp)
            model.train()


def init_model(lm_config):
    tokenizer = AutoTokenizer.from_pretrained('./model/minimind_tokenizer')
    model = MiniMindLM(lm_config)
    moe_path = '_moe' if lm_config.use_moe else ''
    ckp = f'./out/pretrain_{lm_config.dim}{moe_path}.pth'
    state_dict = torch.load(ckp, map_location=args.device)
    model.load_state_dict(state_dict, strict=False)
    Logger(f'LLM总参数量:{sum(p.numel() for p in model.parameters() if p.requires_grad) / 1e6:.3f} 百万')
    model = model.to(args.device)
    return model, tokenizer


def init_distributed_mode():
    if not ddp: return
    global ddp_local_rank, DEVICE

    dist.init_process_group(backend="nccl")
    ddp_rank = int(os.environ["RANK"])
    ddp_local_rank = int(os.environ["LOCAL_RANK"])
    ddp_world_size = int(os.environ["WORLD_SIZE"])
    DEVICE = f"cuda:{ddp_local_rank}"
    torch.cuda.set_device(DEVICE)


if __name__ == "__main__":
    parser = argparse.ArgumentParser(description="MiniMind Full SFT")
    parser.add_argument("--out_dir", type=str, default="out")
    parser.add_argument("--epochs", type=int, default=1)
    parser.add_argument("--batch_size", type=int, default=32)
    parser.add_argument("--learning_rate", type=float, default=5e-5)
    parser.add_argument("--device", type=str, default="cuda:0" if torch.cuda.is_available() else "cpu")
    parser.add_argument("--dtype", type=str, default="bfloat16")
    parser.add_argument("--use_wandb", action="store_true")
    parser.add_argument("--wandb_project", type=str, default="MiniMind-Full-SFT")
    parser.add_argument("--num_workers", type=int, default=1)
    parser.add_argument("--ddp", action="store_true")
    parser.add_argument("--accumulation_steps", type=int, default=1)
    parser.add_argument("--grad_clip", type=float, default=1.0)
    parser.add_argument("--warmup_iters", type=int, default=0)
    parser.add_argument("--log_interval", type=int, default=100)
    parser.add_argument("--save_interval", type=int, default=100)
    parser.add_argument('--local_rank', type=int, default=-1)
    parser.add_argument('--dim', default=512, type=int)
    parser.add_argument('--n_layers', default=8, type=int)
    parser.add_argument('--max_seq_len', default=512, type=int)
    parser.add_argument('--use_moe', default=False, type=bool)
    parser.add_argument("--data_path", type=str, default="./dataset/sft_mini_512.jsonl")

    args = parser.parse_args()

    lm_config = LMConfig(dim=args.dim, n_layers=args.n_layers, max_seq_len=args.max_seq_len, use_moe=args.use_moe)
    args.save_dir = os.path.join(args.out_dir)
    os.makedirs(args.save_dir, exist_ok=True)
    os.makedirs(args.out_dir, exist_ok=True)
    tokens_per_iter = args.batch_size * lm_config.max_seq_len
    device_type = "cuda" if "cuda" in args.device else "cpu"

    args.wandb_run_name = f"MiniMind-Full-SFT-Epoch-{args.epochs}-BatchSize-{args.batch_size}-LearningRate-{args.learning_rate}"

    ctx = nullcontext() if device_type == "cpu" else torch.cuda.amp.autocast()
    ddp = int(os.environ.get("RANK", -1)) != -1  # is this a ddp run?
    ddp_local_rank, DEVICE = 0, "cuda:0"
    base_seed = 1337
    torch.manual_seed(base_seed)
    torch.cuda.manual_seed(base_seed)

    if ddp:
        init_distributed_mode()
        args.device = torch.device(DEVICE)
        rank = dist.get_rank()
        torch.manual_seed(base_seed + rank)
        # 同时设置 CUDA 的随机种子
        torch.cuda.manual_seed(base_seed + rank)

    if args.use_wandb and (not ddp or ddp_local_rank == 0):
        import wandb

        wandb.init(project=args.wandb_project, name=args.wandb_run_name)
    else:
        wandb = None

    model, tokenizer = init_model(lm_config)

    train_ds = SFTDataset(args.data_path, tokenizer, max_length=lm_config.max_seq_len)
    train_sampler = DistributedSampler(train_ds) if ddp else None
    train_loader = DataLoader(
        train_ds,
        batch_size=args.batch_size,
        pin_memory=True,
        drop_last=False,
        shuffle=False,
        num_workers=args.num_workers,
        sampler=train_sampler
    )

    scaler = torch.cuda.amp.GradScaler(enabled=(args.dtype in ['float16', 'bfloat16']))
    optimizer = optim.AdamW(model.parameters(), lr=args.learning_rate)

    if ddp:
        model._ddp_params_and_buffers_to_ignore = {"pos_cis"}
        model = DistributedDataParallel(model, device_ids=[ddp_local_rank])

    iter_per_epoch = len(train_loader)
    for epoch in range(args.epochs):
        train_epoch(epoch, wandb)

Model.py

import math
import struct
import inspect
import time

from .LMConfig import LMConfig
from typing import Any, Optional, Tuple, List, Union
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


class RMSNorm(torch.nn.Module):
    def __init__(self, dim: int, eps: float = 1e-6):
        super().__init__()
        self.eps = eps
        self.weight = nn.Parameter(torch.ones(dim))

    def _norm(self, x):
        return x * torch.rsqrt(x.pow(2).mean(-1, keepdim=True) + self.eps)

    def forward(self, x):
        return self.weight * self._norm(x.float()).type_as(x)


def precompute_pos_cis(dim: int, end: int = int(32 * 1024), theta: float = 1e6):
    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
    return pos_cis


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)

    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)


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)
    )


class Attention(nn.Module):
    def __init__(self, args: LMConfig):
        super().__init__()
        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)
        self.register_buffer("mask", mask, persistent=False)

    def forward(self,
                x: torch.Tensor,
                pos_cis: torch.Tensor,
                past_key_value: Optional[Tuple[torch.Tensor, torch.Tensor]] = None,
                use_cache=False):
        bsz, seq_len, _ = x.shape
        xq, xk, xv = self.wq(x), self.wk(x), self.wv(x)
        xq = xq.view(bsz, seq_len, self.n_local_heads, self.head_dim)
        xk = xk.view(bsz, seq_len, self.n_local_kv_heads, self.head_dim)
        xv = xv.view(bsz, seq_len, self.n_local_kv_heads, self.head_dim)

        xq, xk = apply_rotary_emb(xq, xk, pos_cis)
        # 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

        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)
        )
        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
            )
        else:
            scores = (xq @ xk.transpose(-2, -1)) / math.sqrt(self.head_dim)
            scores += self.mask[:, :, :seq_len, :seq_len]
            scores = F.softmax(scores.float(), dim=-1).type_as(xq)
            scores = self.attn_dropout(scores)
            output = scores @ xv

        output = output.transpose(1, 2).reshape(bsz, seq_len, -1)
        output = self.resid_dropout(self.wo(output))
        return output, past_kv


class FeedForward(nn.Module):
    def __init__(self, config: LMConfig):
        super().__init__()
        if config.hidden_dim is None:
            hidden_dim = 4 * config.dim
            hidden_dim = int(2 * hidden_dim / 3)
            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)

    def forward(self, x):
        return self.dropout(self.w2(F.silu(self.w1(x)) * self.w3(x)))


class MoEGate(nn.Module):
    def __init__(self, config: LMConfig):
        super().__init__()
        self.config = config
        self.top_k = config.num_experts_per_tok
        self.n_routed_experts = config.n_routed_experts

        self.scoring_func = config.scoring_func
        self.alpha = config.aux_loss_alpha
        self.seq_aux = config.seq_aux

        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()

    def reset_parameters(self) -> None:
        import torch.nn.init as init
        init.kaiming_uniform_(self.weight, a=math.sqrt(5))

    def forward(self, hidden_states):
        bsz, seq_len, h = hidden_states.shape
        hidden_states = hidden_states.view(-1, h)
        logits = F.linear(hidden_states, self.weight, None)
        if self.scoring_func == 'softmax':
            scores = logits.softmax(dim=-1)
        else:
            raise NotImplementedError(f'insupportable scoring function for MoE gating: {self.scoring_func}')

        topk_weight, topk_idx = torch.topk(scores, k=self.top_k, dim=-1, sorted=False)

        if self.top_k > 1 and self.norm_topk_prob:
            denominator = topk_weight.sum(dim=-1, keepdim=True) + 1e-20
            topk_weight = topk_weight / denominator

        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:
            aux_loss = 0
        return topk_idx, topk_weight, aux_loss


class MOEFeedForward(nn.Module):
    def __init__(self, config: LMConfig):
        super().__init__()
        self.config = config
        self.experts = nn.ModuleList([
            FeedForward(config)
            for _ in range(config.n_routed_experts)
        ])
        self.gate = MoEGate(config)
        if config.n_shared_experts is not None:
            self.shared_experts = FeedForward(config)

    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):
                y[flat_topk_idx == i] = expert(x[flat_topk_idx == i]).to(y.dtype)  # 确保类型一致
            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)
        self.aux_loss = aux_loss
        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
        # 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
        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]
            expert_out = expert(expert_tokens).to(expert_cache.dtype)
            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


class MiniMindBlock(nn.Module):
    def __init__(self, layer_id: int, config: LMConfig):
        super().__init__()
        self.n_heads = config.n_heads
        self.dim = config.dim
        self.head_dim = config.dim // config.n_heads
        self.attention = Attention(config)

        self.layer_id = layer_id
        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)

    def forward(self, x, pos_cis, past_key_value=None, use_cache=False):
        h_attn, past_kv = self.attention(
            self.attention_norm(x),
            pos_cis,
            past_key_value=past_key_value,
            use_cache=use_cache
        )
        h = x + h_attn
        out = h + self.feed_forward(self.ffn_norm(h))
        return out, past_kv


class MiniMindLM(PreTrainedModel):
    config_class = LMConfig

    def __init__(self, params: LMConfig = None):
        self.params = params or LMConfig()
        super().__init__(self.params)
        self.vocab_size, self.n_layers = params.vocab_size, params.n_layers
        self.tok_embeddings = nn.Embedding(params.vocab_size, params.dim)
        self.dropout = nn.Dropout(params.dropout)
        self.layers = nn.ModuleList([MiniMindBlock(l, params) for l in range(self.n_layers)])
        # RMSNorm(Root Mean Square Layer Normalization)RMSNorm的核心思想是仅通过输入特征的均方根(RMS)进行归一化,而省略了LayerNorm中均值计算和偏移参数的步骤。
        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
        # 将旋转位置编码,暂存值缓存   pos_cis 缓存区名称;precompute_pos_cis(...) 是一个函数调用,用于生成位置编码。 persistent=False 表示这个缓冲区在模型保存和加载时不会被持久化(即不会保存到模型的状态字典中)。
        self.register_buffer("pos_cis",
                             precompute_pos_cis(dim=params.dim // params.n_heads, theta=params.rope_theta),
                             persistent=False)
        # CausalLMOutputWithPast 是 Hugging Face Transformers 库中的一个标准输出类,用于处理因果语言模型(Causal Language Modeling)的输出
        # 包含: 1. logits 2. 过去的键值对 3. 隐藏状态
        # 例如: self.OUT = CausalLMOutputWithPast() ; return self.OUT(logits=logits, past_key_values=past_key_values)
        self.OUT = CausalLMOutputWithPast()

    def forward(self,
                input_ids: Optional[torch.Tensor] = None,
                past_key_values: Optional[List[Tuple[torch.Tensor, torch.Tensor]]] = None,
                use_cache: bool = False,
                logits_to_keep: Union[int, torch.Tensor] = 0,
                **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 = []
        for l, layer in enumerate(self.layers):
            h, past_kv = layer(
                h, pos_cis,
                past_key_value=past_key_values[l],
                use_cache=use_cache
            )
            past_kvs.append(past_kv)

        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, :])
        aux_loss = sum(l.feed_forward.aux_loss for l in self.layers if isinstance(l.feed_forward, MOEFeedForward))
        self.OUT.__setitem__('last_hidden_state', h)
        self.OUT.__setitem__('logits', logits)
        self.OUT.__setitem__('aux_loss', aux_loss)
        self.OUT.__setitem__('past_key_values', past_kvs)
        return self.OUT

    @torch.inference_mode()
    def generate(self, input_ids, eos_token_id=2, max_new_tokens=1024, temperature=0.75, top_p=0.90,
                 stream=False, rp=1., use_cache=True, pad_token_id=0, num_return_sequences=1, **args):
        # 流式生成
        if stream:
            return self._stream(input_ids, eos_token_id, max_new_tokens, temperature, top_p, rp, use_cache, **args)

        # 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)
            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)

        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
        ]
        output = torch.cat(generated, dim=0)
        res = output.view(input_ids.size(0) * num_return_sequences, -1)
        return res

    def _stream(self, input_ids, eos_token_id, max_new_tokens, temperature, top_p, rp, use_cache, **args):
        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:
                out, first_seq = self(input_ids, past_key_values=past_kvs, use_cache=use_cache, **args), False
            else:
                out = self(input_ids[:, -1:], past_key_values=past_kvs, use_cache=use_cache,
                           start_pos=input_ids.shape[1] - 1, **args)
            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:
                break

LMConfig.py

from transformers import PretrainedConfig
from typing import List


class LMConfig(PretrainedConfig):
    model_type = "minimind"

    def __init__(
            self,
            dim: int = 512,
            n_layers: int = 8,
            n_heads: int = 8,
            n_kv_heads: int = 2,
            vocab_size: int = 6400,
            hidden_dim: int = None,
            multiple_of: int = 64,
            norm_eps: float = 1e-5,
            max_seq_len: int = 8192,
            rope_theta: int = 1e6,
            dropout: float = 0.0,
            flash_attn: bool = True,
            ####################################################
            # Here are the specific configurations of MOE
            # When use_moe is false, the following is invalid
            ####################################################
            use_moe: bool = False,
            ####################################################
            num_experts_per_tok: int = 2,
            n_routed_experts: int = 4,
            n_shared_experts: bool = True,
            scoring_func: str = 'softmax',
            aux_loss_alpha: float = 0.1,
            seq_aux: bool = True,
            norm_topk_prob: bool = True,
            **kwargs,
    ):
        self.dim = dim
        self.n_layers = n_layers
        self.n_heads = n_heads
        self.n_kv_heads = n_kv_heads
        self.vocab_size = vocab_size
        self.hidden_dim = hidden_dim
        self.multiple_of = multiple_of
        self.norm_eps = norm_eps
        self.max_seq_len = max_seq_len
        self.rope_theta = rope_theta
        self.dropout = dropout
        self.flash_attn = flash_attn
        ####################################################
        # Here are the specific configurations of MOE
        # When use_moe is false, the following is invalid
        ####################################################
        self.use_moe = use_moe
        self.num_experts_per_tok = num_experts_per_tok  # 每个token选择的专家数量
        self.n_routed_experts = n_routed_experts  # 总的专家数量
        self.n_shared_experts = n_shared_experts  # 共享专家
        self.scoring_func = scoring_func  # 评分函数,默认为'softmax'
        self.aux_loss_alpha = aux_loss_alpha  # 辅助损失的alpha参数
        self.seq_aux = seq_aux  # 是否在序列级别上计算辅助损失
        self.norm_topk_prob = norm_topk_prob  # 是否标准化top-k概率
        super().__init__(**kwargs)

DataSet.py

import json
import random
import re

import pandas as pd
import numpy as np
from torch.utils.data import Dataset, DataLoader
import torch
from sklearn.model_selection import train_test_split
import os
import ast

os.environ["TOKENIZERS_PARALLELISM"] = "false"


class PretrainDataset(Dataset):
    def __init__(self, data_path, tokenizer, max_length=512):
        super().__init__()
        self.tokenizer = tokenizer
        self.max_length = max_length
        self.samples = self.load_data(data_path)

    def load_data(self, path):
        samples = []
        with open(path, 'r', encoding='utf-8') as f:
            for line_num, line in enumerate(f, 1):
                data = json.loads(line.strip())
                samples.append(data)
        return samples

    def __len__(self):
        return len(self.samples)

    def __getitem__(self, index):
        sample = self.samples[index]

        # 1. 构建输入文本
        text = f"{self.tokenizer.bos_token}{str(sample['text'])}{self.tokenizer.eos_token}"
        # 2. 文本编码
        # 使用 tokenizer 对文本进行编码。
        # max_length:设置最大序列长度。
        # padding='max_length':将序列填充到最大长度。
        # truncation=True:如果序列超过最大长度,进行截断。
        # return_tensors='pt':返回 PyTorch 张量。
        encoding = self.tokenizer(
            text,
            max_length=self.max_length,
            padding='max_length',
            truncation=True,
            return_tensors='pt'
        )
        # 3. 提取 input_ids
        # input_ids = encoding.input_ids.squeeze():
        # input_ids 是编码后的词 ID 序列。
        # squeeze() 用于去除多余的维度(如 batch 维度)。
        input_ids = encoding.input_ids.squeeze()

        # 4.生成损失掩码
        # 创建一个掩码,标识哪些位置是实际文本(非填充位置)。
        # 用于在计算损失时忽略填充部分。
        loss_mask = (input_ids != self.tokenizer.pad_token_id)

        # 5. 准备输入和输出
        X = torch.tensor(input_ids[:-1], dtype=torch.long)
        Y = torch.tensor(input_ids[1:], dtype=torch.long)
        # 损失掩码也需要与 Y 对齐,忽略填充部分。
        loss_mask = torch.tensor(loss_mask[1:], dtype=torch.long)
        return X, Y, loss_mask


class SFTDataset(Dataset):
    def __init__(self, jsonl_path, tokenizer, max_length=1024):
        super().__init__()
        self.tokenizer = tokenizer
        self.max_length = max_length
        self.samples = self.load_data(jsonl_path)
        self.bos_id = tokenizer('<s>assistant', add_special_tokens=False).input_ids
        self.eos_id = tokenizer('</s>', add_special_tokens=False).input_ids

    def __len__(self):
        return len(self.samples)

    def load_data(self, path):
        samples = []
        with open(path, 'r', encoding='utf-8') as f:
            for line_num, line in enumerate(f, 1):
                data = json.loads(line.strip())
                samples.append(data)
        return samples

    def _create_chat_prompt(self, conversations):
        """构建符合ChatML格式的对话"""
        messages = []
        for i, turn in enumerate(conversations):
            role = 'user' if i % 2 == 0 else 'assistant'
            messages.append({"role": role, "content": turn['content']})
        return self.tokenizer.apply_chat_template(
            messages,
            tokenize=False,
            add_generation_prompt=False
        )

    def _generate_loss_mask(self, input_ids):
        loss_mask = [0] * len(input_ids)
        i = 0
        while i < len(input_ids):
            if input_ids[i:i + len(self.bos_id)] == self.bos_id:
                start = i + len(self.bos_id)
                end = start
                while end < len(input_ids):
                    if input_ids[end:end + len(self.eos_id)] == self.eos_id:
                        break
                    end += 1
                for j in range(start + 1, min(end + len(self.eos_id) + 1, self.max_length)):
                    loss_mask[j] = 1
                i = end + len(self.eos_id) if end < len(input_ids) else len(input_ids)
            else:
                i += 1
        return loss_mask

    def __getitem__(self, index):
        sample = self.samples[index]
        # 构建对话提示
        prompt = self._create_chat_prompt(sample['conversations'])
        input_ids = self.tokenizer(prompt).input_ids[:self.max_length]
        input_ids += [self.tokenizer.pad_token_id] * (self.max_length - len(input_ids))

        # 生成动态损失掩码
        loss_mask = self._generate_loss_mask(input_ids)

        # 构建训练数据
        X = torch.tensor(input_ids[:-1], dtype=torch.long)
        Y = torch.tensor(input_ids[1:], dtype=torch.long)
        loss_mask = torch.tensor(loss_mask[1:], dtype=torch.long)  # 对齐预测位置

        return X, Y, loss_mask


class DPODataset(Dataset):
    def __init__(self, file_path, tokenizer, max_length=4096):
        super().__init__()
        self.tokenizer = tokenizer
        self.max_length = max_length
        self.padding = tokenizer.pad_token_id if tokenizer.pad_token_id is not None else 0
        self.bos_id = tokenizer('<s>assistant', add_special_tokens=False).input_ids
        self.eos_id = tokenizer('</s>', add_special_tokens=False).input_ids
        with open(file_path, 'r', encoding='utf-8') as f:
            self.data = []
            for line in f:
                line = line.strip()
                obj = json.loads(line)
                self.data.append(obj)

    def __len__(self):
        return len(self.data)

    def __getitem__(self, index):
        item = self.data[index]
        chosen = item['chosen']  # 是一个 list,里面包含若干 {role, content}
        rejected = item['rejected']  # 同上
        chosen_prompt = self.tokenizer.apply_chat_template(
            chosen, tokenize=False, add_generation_prompt=False
        )

        rejected_prompt = self.tokenizer.apply_chat_template(
            rejected, tokenize=False, add_generation_prompt=False
        )
        chosen_encoding = self.tokenizer(
            chosen_prompt, truncation=True, max_length=self.max_length, padding='max_length'
        )
        rejected_encoding = self.tokenizer(
            rejected_prompt, truncation=True, max_length=self.max_length, padding='max_length'
        )

        chosen_input_ids = chosen_encoding['input_ids']
        chosen_loss_mask = self._generate_loss_mask(chosen_input_ids)

        rejected_input_ids = rejected_encoding['input_ids']
        rejected_loss_mask = self._generate_loss_mask(rejected_input_ids)
        x_chosen = torch.tensor(chosen_input_ids[:-1], dtype=torch.long)
        y_chosen = torch.tensor(chosen_input_ids[1:], dtype=torch.long)
        mask_chosen = torch.tensor(chosen_loss_mask[1:], dtype=torch.long)
        x_rejected = torch.tensor(rejected_input_ids[:-1], dtype=torch.long)
        y_rejected = torch.tensor(rejected_input_ids[1:], dtype=torch.long)
        mask_rejected = torch.tensor(rejected_loss_mask[1:], dtype=torch.long)

        return {
            'x_chosen': x_chosen,
            'y_chosen': y_chosen,
            'mask_chosen': mask_chosen,
            'x_rejected': x_rejected,
            'y_rejected': y_rejected,
            'mask_rejected': mask_rejected
        }

    def _generate_loss_mask(self, input_ids):
        loss_mask = [0] * len(input_ids)
        i = 0
        while i < len(input_ids):
            if input_ids[i:i + len(self.bos_id)] == self.bos_id:
                start = i + len(self.bos_id)
                end = start
                while end < len(input_ids):
                    if input_ids[end:end + len(self.eos_id)] == self.eos_id:
                        break
                    end += 1
                for j in range(start + 1, min(end + len(self.eos_id) + 1, self.max_length)):
                    loss_mask[j] = 1
                i = end + len(self.eos_id) if end < len(input_ids) else len(input_ids)
            else:
                i += 1
        return loss_mask


class RLAIFDataset(Dataset):
    def __init__(self, jsonl_path, tokenizer, max_length=1024):
        super().__init__()
        self.tokenizer = tokenizer
        self.max_length = max_length
        self.samples = self.load_data(jsonl_path)
        self.bos_id = tokenizer('<s>assistant', add_special_tokens=False).input_ids
        self.eos_id = tokenizer('</s>', add_special_tokens=False).input_ids

    def __len__(self):
        return len(self.samples)

    def load_data(self, path):
        samples = []
        with open(path, 'r', encoding='utf-8') as f:
            for line_num, line in enumerate(f, 1):
                data = json.loads(line.strip())
                samples.append(data)
        return samples

    def _create_chat_prompt(self, conversations):
        """构建符合ChatML格式的对话"""
        messages = []
        answer = ''
        for i, turn in enumerate(conversations):
            role = 'user' if i % 2 == 0 else 'assistant'
            messages.append({"role": role, "content": turn['content']})
            answer = turn['content']
        return self.tokenizer.apply_chat_template(
            messages[:-1],
            tokenize=False,
            add_generation_prompt=True
        ), answer

    def __getitem__(self, index):
        sample = self.samples[index]
        # 构建对话提示
        prompt, answer = self._create_chat_prompt(sample['conversations'])

        return {
            'prompt': prompt,
            'answer': answer
        }


if __name__ == "__main__":
    pass

4. 开始训练

image-20250428082802126

image-20250428110236883

5. 模型转换

# 5. 模型保存
def convert_torch2transformers(torch_path, transformers_path):
    def export_tokenizer(transformers_path):
        tokenizer = AutoTokenizer.from_pretrained('/root/model/tokenizer')
        tokenizer.save_pretrained(transformers_path)

    LMConfig.register_for_auto_class()
    MiniMindLM.register_for_auto_class("AutoModelForCausalLM")
    lm_model = MiniMindLM(lm_config)
    device = torch.device('cuda' if torch.cuda.is_available() else 'cpu')
    state_dict = torch.load(torch_path, map_location=device)
    lm_model.load_state_dict(state_dict, strict=False)
    model_params = sum(p.numel() for p in lm_model.parameters() if p.requires_grad)
    print(f'模型参数: {model_params / 1e6} 百万 = {model_params / 1e9} B (Billion)')
    lm_model.save_pretrained(transformers_path, safe_serialization=False)
    export_tokenizer(transformers_path)
    print(f"模型已保存为 Transformers 格式: {transformers_path}")
def convert_transformers2torch(transformers_path, torch_path):
    model = AutoModelForCausalLM.from_pretrained(transformers_path, trust_remote_code=True)
    torch.save(model.state_dict(), torch_path)
    print(f"模型已保存为 PyTorch 格式: {torch_path}")
torch_path = '/root/project_finetuneTraining/output/pretrain_512.pth'
transformers_path = '/root/project_finetuneTraining/output/save20250428'
convert_torch2transformers(torch_path, transformers_path)

6. 模型推理

AutoConfig.register('minimind',LMConfig)
AutoModelForCausalLM.register(LMConfig,MiniMindLM)
model_test = AutoModelForCausalLM.from_pretrained('/root/project_finetuneTraining/output/save')
model_test
input_data = tokenizer.apply_chat_template([{"role":"user","content":"中国长城"}])
input_data
for token in model_test.generate(torch.tensor(input_data).unsqueeze(0),tokenizer.eos_token_id,100,stream=False,temperature=0.0,top_k=8):
    print(tokenizer.decode(token))

image-20250428110907935

posted @ 2025-04-28 11:09  付十一。  阅读(54)  评论(0)    收藏  举报