refactor: pass model_fn/optimizer_fn to executor.prepare

- BaseExecutor.prepare now takes factories and instantiates model via model_fn(), runs before_wrap hook, wraps DDP/FSDP, then builds optimizer/scheduler on the wrapped model
- optimizer/scheduler creation moved into executor.prepare, eliminating the old 'create-then-wrap' hack reliance on use_orig_params=True
- FSDPExecutor/BaseExecutor accept **_extra kwargs to tolerate DDP-only keys (broadcast_buffers, gradient_as_bucket_view) being forwarded via executor_kwargs
- dataloader builds stay external; executor only handles model/optimizer/scheduler
- train_context.py rewritten to load checkpoint state_dict before prepare via a before_wrap closure
This commit is contained in:
2026-07-20 01:32:05 +08:00
parent e5f9b1a3a9
commit 74b9308883
2 changed files with 69 additions and 63 deletions
+18 -12
View File
@@ -4,7 +4,7 @@ import contextlib
import logging
import os
from contextlib import contextmanager
from typing import Optional, Tuple
from typing import Callable, Optional, Tuple
import torch
import torch.distributed as dist
@@ -14,7 +14,6 @@ from torch.distributed.fsdp import FullyShardedDataParallel as FSDP
from torch.nn.parallel import DistributedDataParallel as DDP
from torch.optim import Optimizer
from torch.optim.lr_scheduler import LRScheduler
from torch.utils.data import DataLoader
from astrai.factory import BaseFactory
from astrai.parallel.setup import get_rank, get_world_size
@@ -81,24 +80,30 @@ class AccumScheduler:
class BaseExecutor:
def __init__(self, grad_accum_steps: int = 1):
def __init__(self, grad_accum_steps: int = 1, **_extra):
self.gradient_state = GradientState(grad_accum_steps)
def prepare(
self,
model: nn.Module,
optimizer: Optional[Optimizer] = None,
dataloader: Optional[DataLoader] = None,
scheduler: Optional[LRScheduler] = None,
) -> Tuple[
nn.Module, Optional[Optimizer], Optional[DataLoader], Optional[LRScheduler]
]:
model_fn: Callable[[], nn.Module],
optimizer_fn: Optional[Callable[[nn.Module], Optimizer]] = None,
scheduler_fn: Optional[Callable[[Optimizer], LRScheduler]] = None,
before_wrap: Optional[Callable[[nn.Module], nn.Module]] = None,
) -> Tuple[nn.Module, Optional[Optimizer], Optional[LRScheduler]]:
model = model_fn()
if before_wrap is not None:
model = before_wrap(model)
model = self._prepare_model(model)
if optimizer is not None:
optimizer = None
scheduler = None
if optimizer_fn is not None:
optimizer = optimizer_fn(model)
if scheduler_fn is not None:
scheduler = scheduler_fn(optimizer)
optimizer = AccumOptimizer(optimizer, self.gradient_state)
if scheduler is not None:
scheduler = AccumScheduler(scheduler, self.gradient_state)
return model, optimizer, dataloader, scheduler
return model, optimizer, scheduler
def _prepare_model(self, model: nn.Module) -> nn.Module:
return model
@@ -243,6 +248,7 @@ class FSDPExecutor(BaseExecutor):
limit_all_gathers: bool = True,
ignored_states=None,
device_mesh=None,
**_ddp_only_kwargs,
):
super().__init__(grad_accum_steps=grad_accum_steps)
self._fsdp_kwargs = {
+48 -48
View File
@@ -72,61 +72,70 @@ class TrainContextBuilder:
**cfg.executor_kwargs,
)
model = cfg.model_fn()
model = model.to(device=device)
model_config = {}
if self._param_path:
config_path = Path(self._param_path) / "config.json"
if config_path.exists():
model_config = load_json(config_path)
if not model_config and hasattr(model, "config"):
model_config = model.config.to_dict()
preloaded_state_dict = None
preloaded_epoch = cfg.start_epoch
preloaded_consumed = cfg.start_samples * get_world_size()
preloaded_checkpoint = None
if self._param_path:
checkpoint = Checkpoint.load_any(self._param_path)
if checkpoint is not None:
preloaded_state_dict = checkpoint.state_dict
if checkpoint.config:
model_config = checkpoint.config
if self._resume:
preloaded_epoch = checkpoint.epoch or cfg.start_epoch
if checkpoint.consumed_samples > 0:
per_step = (
cfg.batch_per_device
* get_world_size()
* cfg.grad_accum_steps
)
preloaded_consumed = (
checkpoint.consumed_samples // per_step
) * per_step
else:
preloaded_consumed = cfg.start_samples * get_world_size()
preloaded_checkpoint = checkpoint
if not model_config and hasattr(cfg.model_fn(), "config"):
model_config = cfg.model_fn().config.to_dict()
def _before_wrap(m):
m = m.to(device=device)
if preloaded_state_dict is not None:
m.load_state_dict(preloaded_state_dict, strict=False)
if cfg.lora is not None:
inject_lora(
m,
r=cfg.lora.r,
alpha=cfg.lora.alpha,
target_modules=set(cfg.lora.target_modules),
)
return m
context = TrainContext(
model=model,
world_size=get_world_size(),
rank=get_rank(),
config=cfg,
model_config=model_config,
executor=executor,
epoch=preloaded_epoch,
consumed_samples=preloaded_consumed,
checkpoint=preloaded_checkpoint,
)
if self._param_path:
checkpoint = Checkpoint.load_any(self._param_path)
if checkpoint is not None:
model.load_state_dict(checkpoint.state_dict, strict=False)
if checkpoint.config:
context.model_config = checkpoint.config
if self._resume:
context.epoch = checkpoint.epoch or cfg.start_epoch
if checkpoint.consumed_samples > 0:
per_step = (
cfg.batch_per_device
* context.world_size
* cfg.grad_accum_steps
context.model, context.optimizer, context.scheduler = executor.prepare(
cfg.model_fn,
cfg.optimizer_fn,
cfg.scheduler_fn,
before_wrap=_before_wrap,
)
context.consumed_samples = (
checkpoint.consumed_samples // per_step
) * per_step
else:
context.consumed_samples = (
cfg.start_samples * context.world_size
)
context.checkpoint = checkpoint
if cfg.lora is not None:
inject_lora(
model,
r=cfg.lora.r,
alpha=cfg.lora.alpha,
target_modules=set(cfg.lora.target_modules),
)
context.optimizer = cfg.optimizer_fn(model)
context.scheduler = cfg.scheduler_fn(context.optimizer)
train_dataset = cfg.dataset
val_dataset = cfg.val_dataset
@@ -175,15 +184,6 @@ class TrainContextBuilder:
collate_fn=cfg.collate_fn,
)
context.model, context.optimizer, context.dataloader, context.scheduler = (
executor.prepare(
model,
context.optimizer,
context.dataloader,
context.scheduler,
)
)
if context.checkpoint and context.checkpoint.extra:
extra = context.checkpoint.extra
for name in ("optimizer", "scheduler"):