fix: 蒸馏保存段增加 config.json + generation_config.json + tokenizer 三重修复

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bingshuo 2026-05-18 18:06:27 +08:00
parent 9f95ee891d
commit 9e7bc2000a

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@ -7,6 +7,11 @@ Student: Qwen2.5-1.5B (将学会霜砚的思维方式)
使用方法
nohup python3 -u distill_mother.py > distill_mother.log 2>&1 &
配置
- 模型路径需根据实际存储位置修改
- Teacher路径本地或COS上的SFT输出
- Student路径ModelScope/HuggingFace原始模型
"""
import os, json, torch, sys
@ -18,39 +23,58 @@ from datasets import Dataset
from tqdm import tqdm
import torch.nn.functional as F
TEACHER_PATH = "/root/autodl-tmp/output/qwen25-7b-sft/final"
STUDENT_PATH = "/root/autodl-tmp/cache/Qwen/Qwen2___5-1___5B"
DATA = "/root/autodl-tmp/data/sft.jsonl"
# ========== 配置 ==========
TEACHER_PATH = "/root/autodl-tmp/output/qwen25-7b-sft/final" # 母模型SFT输出
STUDENT_PATH = "/root/autodl-tmp/cache/Qwen/Qwen2___5-1___5B" # 1.5B学生
DATA = "/root/autodl-tmp/data/sft.jsonl" # 主语料也可用shuangyan专属语料
OUT = "/root/autodl-tmp/output/qwen25-15b-shuangyan-distill"
EPOCHS = 3; BS = 4; GA = 8; LR = 1e-5; MAX_LEN = 2048; TEMP = 2.0; ALPHA = 0.7
EPOCHS = 3
BS = 4 # 1.5B可以更大batch
GA = 8
LR = 1e-5
MAX_LEN = 2048
TEMP = 2.0 # 蒸馏温度(越高分布越平滑)
ALPHA = 0.7 # 蒸馏loss权重 (0.7蒸馏 + 0.3SFT)
os.makedirs(OUT, exist_ok=True)
# ========== 1. 加载数据 ==========
print("[1/6] Loading data...")
with open(DATA) as f:
raw = [json.loads(line) for line in f]
raw = [{"messages": [m for m in obj["messages"] if m["role"] != "system"]} for obj in raw]
print(f" {len(raw)} examples")
# ========== 2. 加载Teacher + Student ==========
print("[2/6] Loading teacher (7B) and student (1.5B)...")
tokenizer = AutoTokenizer.from_pretrained(STUDENT_PATH, trust_remote_code=True)
tokenizer.pad_token = tokenizer.eos_token
print(" Loading teacher...")
teacher = AutoModelForCausalLM.from_pretrained(TEACHER_PATH, trust_remote_code=True, torch_dtype=torch.bfloat16, attn_implementation="sdpa").cuda()
teacher = AutoModelForCausalLM.from_pretrained(
TEACHER_PATH, trust_remote_code=True,
torch_dtype=torch.bfloat16, attn_implementation="sdpa",
).cuda()
teacher.eval()
for p in teacher.parameters():
p.requires_grad = False
p.requires_grad = False # Teacher不训练
print(f" Teacher: {sum(p.numel() for p in teacher.parameters())/1e9:.2f}B")
print(" Loading student...")
student = AutoModelForCausalLM.from_pretrained(STUDENT_PATH, trust_remote_code=True, torch_dtype=torch.bfloat16, attn_implementation="sdpa").cuda()
student = AutoModelForCausalLM.from_pretrained(
STUDENT_PATH, trust_remote_code=True,
torch_dtype=torch.bfloat16, attn_implementation="sdpa",
).cuda()
student.train()
print(f" Student: {sum(p.numel() for p in student.parameters())/1e9:.2f}B")
print("[3/6] Tokenizing + generating teacher logits...")
# ========== 3. Tokenize生成teacher logits ==========
print("[3/6] Tokenizing data and generating teacher logits...")
processed = []
for d in tqdm(raw, desc="Tokenize"):
for d in tqdm(raw, desc="Tokenize+Teacher"):
ids, labs = [], []
for msg in d["messages"]:
c = msg["content"]
@ -61,40 +85,88 @@ for d in tqdm(raw, desc="Tokenize"):
labs.extend(tok if msg["role"] == "assistant" else [-100] * len(tok))
if len(ids) > MAX_LEN:
ids, labs = ids[:MAX_LEN], labs[:MAX_LEN]
# Teacher生成logits蒸馏目标
with torch.no_grad():
inp = torch.tensor([ids]).cuda()
t_out = teacher(input_ids=inp)
t_logits = t_out.logits[0].float().cpu()
processed.append({"input_ids": ids, "labels": labs, "attention_mask": [1]*len(ids), "teacher_logits": t_logits})
t_logits = t_out.logits[0].float().cpu() # [seq_len, vocab_size]
processed.append({
"input_ids": ids, "labels": labs, "attention_mask": [1]*len(ids),
"teacher_logits": t_logits # 保存teacher的logits
})
ds = Dataset.from_list(processed)
total_tok = sum(len(d["input_ids"]) for d in processed)
print(f" Dataset: {len(ds)} ex, {total_tok:,} tokens")
# ========== 4. 配置训练 ==========
print("[4/6] Training config...")
def distill_collate(features):
"""collate函数处理padding + 蒸馏loss计算"""
max_len = max(len(f["input_ids"]) for f in features)
batch = {}
for k in ["input_ids", "labels", "attention_mask"]:
pad = tokenizer.pad_token_id if k != "labels" else -100
batch[k] = torch.tensor([f[k] + [pad]*(max_len-len(f[k])) for f in features])
# teacher_logits需要特殊padding用0填充
vocab_size = features[0]["teacher_logits"].size(-1)
tl = []
for f in features:
t = f["teacher_logits"]
pad_len = max_len - t.size(0)
tl.append(torch.cat([t, torch.zeros(pad_len, vocab_size)], dim=0) if pad_len > 0 else t[:max_len])
if pad_len > 0:
tl.append(torch.cat([t, torch.zeros(pad_len, vocab_size)], dim=0))
else:
tl.append(t[:max_len])
batch["teacher_logits"] = torch.stack(tl)
return batch
class DistillTrainer(Trainer):
"""自定义Trainer蒸馏loss + SFT loss混合"""
def compute_loss(self, model, inputs, return_outputs=False, **kwargs):
outputs = model(input_ids=inputs["input_ids"], attention_mask=inputs["attention_mask"], use_cache=False)
student_logits = outputs.logits
# 前向传播
outputs = model(
input_ids=inputs["input_ids"],
attention_mask=inputs["attention_mask"],
use_cache=False,
)
student_logits = outputs.logits # [batch, seq_len, vocab_size]
# SFT loss (交叉熵只计算assistant部分)
shift_logits = student_logits[..., :-1, :].contiguous()
shift_labels = inputs["labels"][..., 1:].contiguous()
sft_loss = F.cross_entropy(shift_logits.view(-1, shift_logits.size(-1)), shift_labels.view(-1), ignore_index=-100, reduction="mean")
teacher_logits = inputs["teacher_logits"]
mask = (inputs["labels"] != -100).unsqueeze(-1).float()
kl_loss = F.kl_div(F.log_softmax(student_logits / TEMP, dim=-1), F.softmax(teacher_logits / TEMP, dim=-1), reduction="none")
kl_loss = (kl_loss * mask).sum() / mask.sum() * (TEMP ** 2)
return ALPHA * kl_loss + (1 - ALPHA) * sft_loss
sft_loss = F.cross_entropy(
shift_logits.view(-1, shift_logits.size(-1)),
shift_labels.view(-1),
ignore_index=-100,
reduction="mean",
)
# KL蒸馏lossteacher vs student
teacher_logits = inputs["teacher_logits"] # [batch, seq_len, vocab_size]
# 只对assistant部分计算KL
mask = (inputs["labels"] != -100).unsqueeze(-1).float() # [batch, seq_len, 1]
# 软化分布
s_logits_soft = student_logits / TEMP
t_logits_soft = teacher_logits / TEMP
kl_loss = F.kl_div(
F.log_softmax(s_logits_soft, dim=-1),
F.softmax(t_logits_soft, dim=-1),
reduction="none",
)
kl_loss = (kl_loss * mask).sum() / mask.sum()
kl_loss = kl_loss * (TEMP ** 2) # 温度缩放
# 混合loss
total_loss = ALPHA * kl_loss + (1 - ALPHA) * sft_loss
return total_loss
args = TrainingArguments(
output_dir=OUT, num_train_epochs=EPOCHS,
@ -107,19 +179,51 @@ args = TrainingArguments(
report_to="none", ddp_find_unused_parameters=False,
)
trainer = DistillTrainer(model=student, args=args, train_dataset=Dataset.from_list(processed), data_collator=distill_collate)
trainer = DistillTrainer(
model=student, args=args,
train_dataset=ds, data_collator=distill_collate,
)
# ========== 5. 启动训练 ==========
print("[5/6] Starting distillation!")
gpu = torch.cuda.get_device_name(0)
mem = torch.cuda.get_device_properties(0).total_memory / 1e9
print(f" GPU: {gpu} ({mem:.1f}GB) | Temp={TEMP}, Alpha={ALPHA}")
t_params = sum(p.numel() for p in teacher.parameters())
s_params = sum(p.numel() for p in student.parameters())
print(f" GPU: {gpu} ({mem:.1f}GB)")
print(f" Teacher: {t_params/1e9:.2f}B | Student: {s_params/1e9:.2f}B")
print(f" Temp={TEMP}, Alpha={ALPHA}, Eff batch={BS*GA}, LR={LR}")
sys.stdout.flush()
trainer.train()
print("[6/6] Saving...")
# ========== 6. 保存 ==========
print("[6/6] Saving distilled model...")
final = os.path.join(OUT, "final")
trainer.save_model(final)
tokenizer.save_pretrained(final)
# ⚠️ 关键修复Qwen chat template 使用 <|im_end|> (151645) 作为对话EOS
# 但默认 eos_token_id=151643 (<|endoftext|>)
# 不修复会导致部署时模型无限生成 → 死循环乱码
# 注意:必须同时修复 config.json 和 generation_config.json
model.config.eos_token_id = 151645
model.config.save_pretrained(final)
model.generation_config.eos_token_id = 151645
model.generation_config.pad_token_id = 151645
model.generation_config.save_pretrained(final)
# 修复 tokenizer 默认system prompt避免 "You are Qwen..."
import json as _json
_tok_cfg_path = os.path.join(final, "tokenizer_config.json")
with open(_tok_cfg_path) as _f:
_tok_cfg = _json.load(_f)
_tok_cfg["default_system"] = ""
with open(_tok_cfg_path, "w") as _f:
_json.dump(_tok_cfg, _f, indent=2, ensure_ascii=False)
peak = torch.cuda.max_memory_allocated() / 1e9
print(f" Model: {final} | Peak VRAM: {peak:.2f}GB / {mem:.1f}GB")
print(f" Model: {final}")
print(f" Peak VRAM: {peak:.2f}GB / {mem:.1f}GB")
print("DONE!")