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Author SHA1 Message Date
Neil Ge 08e1bdb9d8
Merge 9cb07dd1ec into 7a9137d2e9 2026-09-15 19:34:49 +08:00
jingyaogong 7a9137d2e9 [update] trim verbose ddp comments 2026-09-15 14:53:11 +08:00
jingyaogong 7988bc81a3
Merge pull request #855 from basil-k-aji-dev/perf/ddp-followups
[perf] skip the per-forward RoPE buffer broadcast in the RL trainers
2026-09-15 14:51:37 +08:00
basil-k-aji-dev 37ac206e9a [perf] skip the per-forward RoPE buffer broadcast in the RL trainers
Follow-up to the review on #854.

DDP re-broadcasts every registered buffer from rank 0 on each forward. The only
buffers here are freqs_cos / freqs_sin, which each rank computes deterministically
from config and never mutates from data, so the broadcast moves identical bytes
every step for nothing.

Verified with a two-rank CPU/Gloo run: with broadcast_buffers=False the
gradients stay identical across ranks and so do the buffers.

Also document the critic's tied-embedding assumption. CriticModel.forward never
calls lm_head, which is only safe under DDP because tie_word_embeddings (default
True) makes lm_head.weight the same Parameter as embed_tokens.weight. Untied, it
becomes a genuinely unused parameter and DDP raises.
2026-09-14 22:22:00 +05:30
jingyaogong 21ec325dba [update] simplify safe math eval 2026-09-14 23:55:32 +08:00
neil.ge 9cb07dd1ec perf: enable fused AdamW in pretrain training
Same fused AdamW optimization as the full SFT script, using the
existing device_type variable so the CPU-only path is unaffected.

Co-authored-by: TRAE CLI <traecli@bytedance.com>
2026-09-05 19:16:51 +08:00
neil.ge 859c8ee2a3 perf: enable fused AdamW in full SFT training
Use PyTorch's fused AdamW implementation to reduce optimizer kernel
launch overhead and speed up the training step on CUDA devices.
Guard with device check so the CPU-only fallback path is unaffected.

Co-authored-by: TRAE CLI <traecli@bytedance.com>
2026-09-05 18:37:04 +08:00
6 changed files with 37 additions and 53 deletions

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@ -473,7 +473,8 @@ if __name__ == "__main__":
Logger('torch.compile enabled')
rollout_engine.update_policy(model)
if dist.is_initialized():
model = DistributedDataParallel(model, device_ids=[local_rank])
# 同 train_ppo:RoPE buffer 各 rank 一致,每步广播纯属浪费
model = DistributedDataParallel(model, device_ids=[local_rank], broadcast_buffers=False)
rollout_engine.update_policy(model)
for epoch in range(start_epoch, args.epochs):

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@ -137,7 +137,7 @@ if __name__ == "__main__":
train_ds = SFTDataset(args.data_path, tokenizer, max_length=args.max_seq_len)
train_sampler = DistributedSampler(train_ds) if dist.is_initialized() else None
scaler = torch.cuda.amp.GradScaler(enabled=(args.dtype == 'float16'))
optimizer = optim.AdamW(model.parameters(), lr=args.learning_rate)
optimizer = optim.AdamW(model.parameters(), lr=args.learning_rate, fused=('cuda' in args.device))
# ========== 6. 从ckp恢复状态 ==========
start_epoch, start_step = 0, 0

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@ -314,7 +314,8 @@ if __name__ == "__main__":
Logger('torch.compile enabled')
rollout_engine.update_policy(model)
if dist.is_initialized():
model = DistributedDataParallel(model, device_ids=[local_rank])
# 同 train_ppo:RoPE buffer 各 rank 一致,每步广播纯属浪费
model = DistributedDataParallel(model, device_ids=[local_rank], broadcast_buffers=False)
rollout_engine.update_policy(model)
# ========== 8. 开始训练 ==========

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@ -36,7 +36,7 @@ def rep_penalty(text, n=3, cap=0.5):
class CriticModel(MiniMindForCausalLM):
def __init__(self, params):
super().__init__(params)
# 替换lm_head为输出单一价值的线性层
# lm_head 不参与 forward,仅靠 tie_word_embeddings 与 embed_tokens 共享权重,解绑后 DDP 会报未使用参数
self.value_head = nn.Linear(params.hidden_size, 1)
def forward(self, input_ids=None, attention_mask=None, **kwargs):
@ -429,8 +429,9 @@ if __name__ == "__main__":
Logger('torch.compile enabled')
rollout_engine.update_policy(actor_model)
if dist.is_initialized():
actor_model = DistributedDataParallel(actor_model, device_ids=[local_rank])
critic_model = DistributedDataParallel(critic_model, device_ids=[local_rank])
# freqs_cos/freqs_sin 各 rank 由 config 确定性算出,默认每步广播一次纯属浪费
actor_model = DistributedDataParallel(actor_model, device_ids=[local_rank], broadcast_buffers=False)
critic_model = DistributedDataParallel(critic_model, device_ids=[local_rank], broadcast_buffers=False)
rollout_engine.update_policy(actor_model)
# ========== 8. 开始训练 ==========

View File

@ -136,7 +136,7 @@ if __name__ == "__main__":
train_ds = PretrainDataset(args.data_path, tokenizer, max_length=args.max_seq_len)
train_sampler = DistributedSampler(train_ds) if dist.is_initialized() else None
scaler = torch.cuda.amp.GradScaler(enabled=(args.dtype == 'float16'))
optimizer = optim.AdamW(model.parameters(), lr=args.learning_rate)
optimizer = optim.AdamW(model.parameters(), lr=args.learning_rate, fused=(device_type == 'cuda'))
# ========== 6. 从ckp恢复状态 ==========
start_epoch, start_step = 0, 0

View File

@ -179,50 +179,31 @@ class LMForRewardModel:
return max(min(score, 3.0), -3.0)
# ===== 数学表达式安全求值(替代 eval,避免执行模型生成的任意代码) =====
_MATH_FUNCS = {name: getattr(math, name) for name in (
'sqrt', 'pow', 'exp', 'log', 'log2', 'log10', 'sin', 'cos', 'tan', 'asin', 'acos', 'atan', 'atan2',
'sinh', 'cosh', 'tanh', 'floor', 'ceil', 'trunc', 'fabs', 'fmod', 'hypot', 'gcd', 'degrees', 'radians'
)}
_MATH_CONSTS = {'pi': math.pi, 'e': math.e, 'tau': math.tau}
_BIN_OPS = {ast.Add: operator.add, ast.Sub: operator.sub, ast.Mult: operator.mul, ast.Div: operator.truediv,
ast.FloorDiv: operator.floordiv, ast.Mod: operator.mod, ast.Pow: operator.pow}
_UNARY_OPS = {ast.UAdd: operator.pos, ast.USub: operator.neg}
_MAX_EXPR_LEN, _MAX_EXP, _MAX_DIGITS = 512, 1e4, 100 # 表达式长度 / 指数 / 结果位数上限
def _check_pow(base, exp): # 防止 9**9**9 这类表达式把进程算死
if abs(exp) > _MAX_EXP or (abs(base) > 1 and abs(exp) * math.log10(abs(base)) > _MAX_DIGITS):
raise ValueError('幂运算结果过大')
def _resolve_name(node): # 同时兼容 sqrt(4) 与 math.sqrt(4) 两种写法
if isinstance(node, ast.Name): return node.id
if isinstance(node, ast.Attribute) and isinstance(node.value, ast.Name) and node.value.id == 'math': return node.attr
return None
def _eval_ast(node):
if isinstance(node, ast.Constant) and isinstance(node.value, (int, float)) and not isinstance(node.value, bool):
return node.value
if isinstance(node, (ast.Name, ast.Attribute)) and _resolve_name(node) in _MATH_CONSTS:
return _MATH_CONSTS[_resolve_name(node)]
if isinstance(node, ast.UnaryOp) and type(node.op) in _UNARY_OPS:
return _UNARY_OPS[type(node.op)](_eval_ast(node.operand))
if isinstance(node, ast.BinOp) and type(node.op) in _BIN_OPS:
left, right = _eval_ast(node.left), _eval_ast(node.right)
if isinstance(node.op, ast.Pow): _check_pow(left, right)
return _BIN_OPS[type(node.op)](left, right)
if isinstance(node, ast.Call) and _resolve_name(node.func) in _MATH_FUNCS and not node.keywords:
name, args = _resolve_name(node.func), [_eval_ast(arg) for arg in node.args]
if name == 'pow' and len(args) == 2: _check_pow(*args)
return _MATH_FUNCS[name](*args)
raise ValueError(f'不支持的表达式语法: {type(node).__name__}')
# ===== 数学表达式安全求值:替代 eval,只放行算术运算与 math 白名单(长度上限 512) =====
def safe_math_eval(expression):
"""对模型生成的数学表达式求值:只放行算术运算与 math 白名单函数,不执行任意代码。"""
expr = str(expression).replace('^', '**').replace('×', '*').replace('÷', '/').replace('−', '-')
expr = expr.replace('²', '**2').replace('³', '**3').replace('(', '(').replace(')', ')').strip()
if not expr or len(expr) > _MAX_EXPR_LEN: raise ValueError('表达式为空或过长')
return _eval_ast(ast.parse(expr, mode='eval').body)
"""对模型生成的数学表达式求值:支持 + - * / // % **、math 白名单函数与 pi/e/tau 常量。"""
def pow_guard(base, exp): # 幂运算统一走这里,拦截 9**9**9 / 10**99999 这类把进程算死的输入
if abs(exp) > 1e4 or (abs(base) > 1 and abs(exp) * math.log10(abs(base)) > 100): raise ValueError('幂运算结果过大')
return base ** exp
def resolve(node): # 同时兼容 sqrt(4) 与 math.sqrt(4) 两种写法
if isinstance(node, ast.Name): return node.id
if isinstance(node, ast.Attribute) and getattr(node.value, 'id', '') == 'math': return node.attr
def walk(node):
if isinstance(node, ast.Constant) and type(node.value) in (int, float): return node.value
name = resolve(node)
if name in consts: return consts[name]
if isinstance(node, ast.UnaryOp): return unary_ops[type(node.op)](walk(node.operand))
if isinstance(node, ast.BinOp): return bin_ops[type(node.op)](walk(node.left), walk(node.right))
if isinstance(node, ast.Call) and not node.keywords: return funcs[resolve(node.func)](*map(walk, node.args))
raise ValueError(f'不支持的表达式语法: {type(node).__name__}')
consts = {'pi': math.pi, 'e': math.e, 'tau': math.tau}
funcs = {'pow': pow_guard, **{n: getattr(math, n) for n in 'sqrt exp log log2 log10 sin cos tan asin acos atan atan2 sinh cosh tanh floor ceil trunc fabs fmod hypot gcd degrees radians'.split()}}
bin_ops = {ast.Add: operator.add, ast.Sub: operator.sub, ast.Mult: operator.mul, ast.Div: operator.truediv, ast.FloorDiv: operator.floordiv, ast.Mod: operator.mod, ast.Pow: pow_guard}
unary_ops = {ast.UAdd: operator.pos, ast.USub: operator.neg}
chars = str.maketrans({'^': '**', '×': '*', '÷': '/', '−': '-', '²': '**2', '³': '**3', '(': '(', ')': ')'})
expr = str(expression).translate(chars).strip()
if not expr or len(expr) > 512: raise ValueError('表达式为空或过长')
try:
return walk(ast.parse(expr, mode='eval').body)
except (KeyError, SyntaxError, TypeError):
raise ValueError('不支持的表达式语法') from None