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AstrAI/astrai/optim/muon_adamw.py
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ViperEkura 11073bd1d2 refactor: extract composite optimizer helpers and unify naming
- add astrai/optim/composite.py with shared step/zero_grad/state_dict/param_groups helpers and OptimizerFactory
- rename MuonMix to MuonAdamW (matches registered name muon_adamw) and file to muon_adamw.py
- use @OptimizerFactory.register decorator in each optimizer module instead of post-import registration in __init__
- fix closure being invoked once per sub-optimizer in MuonAdamW.step (now exactly once via composite_step)
- NoraNAdamW.step now forwards closure correctly
2026-08-01 08:07:45 +08:00

96 lines
2.9 KiB
Python

"""Legacy Muon + AdamW combined optimizer."""
from typing import Any
import torch
from torch import Tensor, nn, optim
from astrai.optim.composite import (
OptimizerFactory,
composite_state_dict,
composite_step,
composite_zero_grad,
refresh_param_groups,
)
@OptimizerFactory.register("muon_adamw")
class MuonAdamW(optim.Optimizer):
"""Combined Muon (matrix) + AdamW (non-matrix) optimizer."""
optimizer_name = "muon_adamw"
def __init__(
self,
model: nn.Module,
lr: float = 3e-4,
weight_decay: float = 0.1,
momentum: float = 0.95,
nesterov: bool = True,
ns_steps: int = 5,
adjust_lr_fn: str = "match_rms_adamw",
):
defaults = {
"lr": lr,
"weight_decay": weight_decay,
"momentum": momentum,
"nesterov": nesterov,
"ns_steps": ns_steps,
"adjust_lr_fn": adjust_lr_fn,
}
params = [param for param in model.parameters() if param.requires_grad]
super().__init__(params, defaults)
matrix_params: list[Tensor] = []
other_params: list[Tensor] = []
for name, param in model.named_parameters():
if not param.requires_grad:
continue
if (
param.dim() >= 2
and "norm" not in name
and "bias" not in name
and "embed" not in name
and "lm_head" not in name
):
matrix_params.append(param)
else:
other_params.append(param)
self.muon = optim.Muon(
matrix_params,
lr=lr,
weight_decay=weight_decay,
momentum=momentum,
nesterov=nesterov,
ns_steps=ns_steps,
adjust_lr_fn=adjust_lr_fn,
)
self.adamw = optim.AdamW(
[{"params": other_params, "weight_decay": 0.0}],
lr=lr,
betas=(0.9, 0.95),
fused=True,
)
self.param_groups = refresh_param_groups([self.muon, self.adamw])
@torch.no_grad()
def step(self, closure=None):
return composite_step([self.muon, self.adamw], closure)
def zero_grad(self, set_to_none: bool = True):
composite_zero_grad([self.muon, self.adamw], set_to_none)
def state_dict(self) -> dict[str, Any]:
return composite_state_dict({"muon": self.muon, "adamw": self.adamw})
def load_state_dict(self, state_dict: dict[str, Any]):
if "muon" not in state_dict or "adamw" not in state_dict:
raise ValueError(
"Checkpoint optimizer state is not compatible with muon_adamw"
)
self.muon.load_state_dict(state_dict["muon"])
self.adamw.load_state_dict(state_dict["adamw"])
self.param_groups = refresh_param_groups([self.muon, self.adamw])