add accelerate

This commit is contained in:
Pepijn
2025-09-23 22:06:30 +02:00
parent 0be09c4080
commit 199f3b927b
2 changed files with 192 additions and 81 deletions

View File

@@ -63,6 +63,10 @@ class TrainPipelineConfig(HubMixin):
scheduler: LRSchedulerConfig | None = None
eval: EvalConfig = field(default_factory=EvalConfig)
wandb: WandBConfig = field(default_factory=WandBConfig)
# Accelerate configuration for multi-GPU training
use_accelerate: bool = False
gradient_accumulation_steps: int = 1
mixed_precision: str = "no" # Options: "no", "fp16", "bf16"
def __post_init__(self):
self.checkpoint_path = None

View File

@@ -20,6 +20,7 @@ from pprint import pformat
from typing import Any
import torch
from accelerate import Accelerator
from termcolor import colored
from torch.amp import GradScaler
from torch.optim import Optimizer
@@ -64,6 +65,7 @@ def update_policy(
lr_scheduler=None,
use_amp: bool = False,
lock=None,
accelerator: Accelerator = None,
) -> tuple[MetricsTracker, dict]:
"""
Performs a single training step to update the policy's weights.
@@ -90,28 +92,48 @@ def update_policy(
start_time = time.perf_counter()
device = get_device_from_parameters(policy)
policy.train()
with torch.autocast(device_type=device.type) if use_amp else nullcontext():
loss, output_dict = policy.forward(batch)
# TODO(rcadene): policy.unnormalize_outputs(out_dict)
grad_scaler.scale(loss).backward()
# Unscale the gradient of the optimizer's assigned params in-place **prior to gradient clipping**.
grad_scaler.unscale_(optimizer)
# Handle mixed precision differently for accelerate vs non-accelerate
if accelerator is not None:
# Accelerate handles mixed precision internally
with accelerator.autocast() if use_amp else nullcontext():
loss, output_dict = policy.forward(batch)
# Use accelerator's backward method
accelerator.backward(loss)
else:
# Original behavior for non-accelerate
with torch.autocast(device_type=device.type) if use_amp else nullcontext():
loss, output_dict = policy.forward(batch)
# TODO(rcadene): policy.unnormalize_outputs(out_dict)
grad_scaler.scale(loss).backward()
grad_norm = torch.nn.utils.clip_grad_norm_(
policy.parameters(),
grad_clip_norm,
error_if_nonfinite=False,
)
if accelerator is not None:
# Accelerate handles gradient scaling internally
grad_norm = accelerator.clip_grad_norm_(policy.parameters(), grad_clip_norm)
if grad_norm is None:
grad_norm = 0.0
with lock if lock is not None else nullcontext():
optimizer.step()
optimizer.zero_grad()
else:
# Original gradient handling for non-accelerate
# Unscale the gradient of the optimizer's assigned params in-place **prior to gradient clipping**.
grad_scaler.unscale_(optimizer)
# Optimizer's gradients are already unscaled, so scaler.step does not unscale them,
# although it still skips optimizer.step() if the gradients contain infs or NaNs.
with lock if lock is not None else nullcontext():
grad_scaler.step(optimizer)
# Updates the scale for next iteration.
grad_scaler.update()
grad_norm = torch.nn.utils.clip_grad_norm_(
policy.parameters(),
grad_clip_norm,
error_if_nonfinite=False,
)
optimizer.zero_grad()
# Optimizer's gradients are already unscaled, so scaler.step does not unscale them,
# although it still skips optimizer.step() if the gradients contain infs or NaNs.
with lock if lock is not None else nullcontext():
grad_scaler.step(optimizer)
# Updates the scale for next iteration.
grad_scaler.update()
optimizer.zero_grad()
# Step through pytorch scheduler at every batch instead of epoch
if lr_scheduler is not None:
@@ -147,6 +169,19 @@ def train(cfg: TrainPipelineConfig):
cfg.validate()
logging.info(pformat(cfg.to_dict()))
# Initialize Accelerate if requested
accelerator = None
if cfg.use_accelerate:
accelerator = Accelerator(
gradient_accumulation_steps=cfg.gradient_accumulation_steps,
mixed_precision=cfg.mixed_precision,
)
device = accelerator.device
logging.info(f"Accelerate initialized with device: {device}, mixed_precision: {cfg.mixed_precision}")
else:
# Check device is available (original behavior)
device = get_safe_torch_device(cfg.policy.device, log=True)
if cfg.wandb.enable and cfg.wandb.project:
wandb_logger = WandBLogger(cfg)
else:
@@ -156,8 +191,6 @@ def train(cfg: TrainPipelineConfig):
if cfg.seed is not None:
set_seed(cfg.seed)
# Check device is available
device = get_safe_torch_device(cfg.policy.device, log=True)
torch.backends.cudnn.benchmark = True
torch.backends.cuda.matmul.allow_tf32 = True
@@ -198,6 +231,13 @@ def train(cfg: TrainPipelineConfig):
step = 0 # number of policy updates (forward + backward + optim)
if cfg.resume:
if accelerator is not None:
# Load accelerate-specific state if available
accelerate_state_path = cfg.checkpoint_path / "accelerate_state"
if accelerate_state_path.exists():
accelerator.load_state(str(accelerate_state_path))
logging.info("Loaded Accelerate state from checkpoint")
step, optimizer, lr_scheduler = load_training_state(cfg.checkpoint_path, optimizer, lr_scheduler)
num_learnable_params = sum(p.numel() for p in policy.parameters() if p.requires_grad)
@@ -235,6 +275,14 @@ def train(cfg: TrainPipelineConfig):
drop_last=False,
prefetch_factor=2,
)
# Prepare objects with Accelerate if enabled
if accelerator is not None:
policy, optimizer, dataloader, lr_scheduler = accelerator.prepare(
policy, optimizer, dataloader, lr_scheduler
)
logging.info("Policy, optimizer, dataloader, and scheduler prepared with Accelerate")
dl_iter = cycle(dataloader)
policy.train()
@@ -253,21 +301,42 @@ def train(cfg: TrainPipelineConfig):
logging.info("Start offline training on a fixed dataset")
for _ in range(step, cfg.steps):
start_time = time.perf_counter()
batch = next(dl_iter)
batch = preprocessor(batch)
train_tracker.dataloading_s = time.perf_counter() - start_time
# Handle gradient accumulation
if accelerator is not None:
with accelerator.accumulate(policy):
start_time = time.perf_counter()
batch = next(dl_iter)
batch = preprocessor(batch)
train_tracker.dataloading_s = time.perf_counter() - start_time
train_tracker, output_dict = update_policy(
train_tracker,
policy,
batch,
optimizer,
cfg.optimizer.grad_clip_norm,
grad_scaler=grad_scaler,
lr_scheduler=lr_scheduler,
use_amp=cfg.policy.use_amp,
)
train_tracker, output_dict = update_policy(
train_tracker,
policy,
batch,
optimizer,
cfg.optimizer.grad_clip_norm,
grad_scaler=grad_scaler,
lr_scheduler=lr_scheduler,
use_amp=cfg.policy.use_amp,
accelerator=accelerator,
)
else:
start_time = time.perf_counter()
batch = next(dl_iter)
batch = preprocessor(batch)
train_tracker.dataloading_s = time.perf_counter() - start_time
train_tracker, output_dict = update_policy(
train_tracker,
policy,
batch,
optimizer,
cfg.optimizer.grad_clip_norm,
grad_scaler=grad_scaler,
lr_scheduler=lr_scheduler,
use_amp=cfg.policy.use_amp,
accelerator=accelerator,
)
# Note: eval and checkpoint happens *after* the `step`th training update has completed, so we
# increment `step` here.
@@ -289,63 +358,101 @@ def train(cfg: TrainPipelineConfig):
if cfg.save_checkpoint and is_saving_step:
logging.info(f"Checkpoint policy after step {step}")
checkpoint_dir = get_step_checkpoint_dir(cfg.output_dir, cfg.steps, step)
save_checkpoint(
checkpoint_dir, step, cfg, policy, optimizer, lr_scheduler, preprocessor, postprocessor
)
update_last_checkpoint(checkpoint_dir)
if wandb_logger:
wandb_logger.log_policy(checkpoint_dir)
if accelerator is not None:
# Use accelerate's checkpointing - only saves on main process
accelerator.wait_for_everyone() # Synchronize all processes
if accelerator.is_main_process:
# Use unwrapped model for saving
unwrapped_policy = accelerator.unwrap_model(policy)
save_checkpoint(
checkpoint_dir,
step,
cfg,
unwrapped_policy,
optimizer,
lr_scheduler,
preprocessor,
postprocessor,
)
update_last_checkpoint(checkpoint_dir)
if wandb_logger:
wandb_logger.log_policy(checkpoint_dir)
# Save accelerate-specific state
accelerator.save_state(checkpoint_dir / "accelerate_state")
else:
# Original behavior for non-accelerate
save_checkpoint(
checkpoint_dir, step, cfg, policy, optimizer, lr_scheduler, preprocessor, postprocessor
)
update_last_checkpoint(checkpoint_dir)
if wandb_logger:
wandb_logger.log_policy(checkpoint_dir)
if cfg.env and is_eval_step:
step_id = get_step_identifier(step, cfg.steps)
logging.info(f"Eval policy at step {step}")
with (
torch.no_grad(),
torch.autocast(device_type=device.type) if cfg.policy.use_amp else nullcontext(),
):
eval_info = eval_policy_all(
envs=eval_env, # dict[suite][task_id] -> vec_env
policy=policy,
preprocessor=preprocessor,
postprocessor=postprocessor,
n_episodes=cfg.eval.n_episodes,
videos_dir=cfg.output_dir / "eval" / f"videos_step_{step_id}",
max_episodes_rendered=4,
start_seed=cfg.seed,
max_parallel_tasks=cfg.env.max_parallel_tasks,
# Only evaluate on main process when using accelerate
if accelerator is None or accelerator.is_main_process:
step_id = get_step_identifier(step, cfg.steps)
logging.info(f"Eval policy at step {step}")
# Use unwrapped model for evaluation if using accelerate
eval_policy = accelerator.unwrap_model(policy) if accelerator is not None else policy
with (
torch.no_grad(),
torch.autocast(device_type=device.type) if cfg.policy.use_amp else nullcontext(),
):
eval_info = eval_policy_all(
envs=eval_env, # dict[suite][task_id] -> vec_env
policy=eval_policy,
preprocessor=preprocessor,
postprocessor=postprocessor,
n_episodes=cfg.eval.n_episodes,
videos_dir=cfg.output_dir / "eval" / f"videos_step_{step_id}",
max_episodes_rendered=4,
start_seed=cfg.seed,
max_parallel_tasks=cfg.env.max_parallel_tasks,
)
# overall metrics (suite-agnostic)
aggregated = eval_info["overall"]
# optional: per-suite logging
for suite, suite_info in eval_info.items():
logging.info("Suite %s aggregated: %s", suite, suite_info)
# meters/tracker
eval_metrics = {
"avg_sum_reward": AverageMeter("∑rwrd", ":.3f"),
"pc_success": AverageMeter("success", ":.1f"),
"eval_s": AverageMeter("eval_s", ":.3f"),
}
eval_tracker = MetricsTracker(
cfg.batch_size, dataset.num_frames, dataset.num_episodes, eval_metrics, initial_step=step
)
# overall metrics (suite-agnostic)
aggregated = eval_info["overall"]
eval_tracker.eval_s = aggregated.pop("eval_s")
eval_tracker.avg_sum_reward = aggregated.pop("avg_sum_reward")
eval_tracker.pc_success = aggregated.pop("pc_success")
if wandb_logger:
wandb_log_dict = {**eval_tracker.to_dict(), **eval_info}
wandb_logger.log_dict(wandb_log_dict, step, mode="eval")
wandb_logger.log_video(eval_info["overall"]["video_paths"][0], step, mode="eval")
# optional: per-suite logging
for suite, suite_info in eval_info.items():
logging.info("Suite %s aggregated: %s", suite, suite_info)
# meters/tracker
eval_metrics = {
"avg_sum_reward": AverageMeter("∑rwrd", ":.3f"),
"pc_success": AverageMeter("success", ":.1f"),
"eval_s": AverageMeter("eval_s", ":.3f"),
}
eval_tracker = MetricsTracker(
cfg.batch_size, dataset.num_frames, dataset.num_episodes, eval_metrics, initial_step=step
)
eval_tracker.eval_s = aggregated.pop("eval_s")
eval_tracker.avg_sum_reward = aggregated.pop("avg_sum_reward")
eval_tracker.pc_success = aggregated.pop("pc_success")
if wandb_logger:
wandb_log_dict = {**eval_tracker.to_dict(), **eval_info}
wandb_logger.log_dict(wandb_log_dict, step, mode="eval")
wandb_logger.log_video(eval_info["overall"]["video_paths"][0], step, mode="eval")
# Synchronize all processes after evaluation
if accelerator is not None:
accelerator.wait_for_everyone()
if eval_env:
close_envs(eval_env)
logging.info("End of training")
if cfg.policy.push_to_hub:
policy.push_model_to_hub(cfg)
preprocessor.push_to_hub(cfg.policy.repo_id)
postprocessor.push_to_hub(cfg.policy.repo_id)
# Only push to hub from main process when using accelerate
if accelerator is None or accelerator.is_main_process:
# Use unwrapped model for hub pushing if using accelerate
hub_policy = accelerator.unwrap_model(policy) if accelerator is not None else policy
hub_policy.push_model_to_hub(cfg)
preprocessor.push_to_hub(cfg.policy.repo_id)
postprocessor.push_to_hub(cfg.policy.repo_id)
def main():