ColossalAI/applications/Chat/coati/ray/detached_trainer_ppo.py

192 lines
8.5 KiB
Python

from typing import Callable, Dict, List, Tuple
import ray
import torch
from coati.experience_maker import Experience
from coati.models.base import Actor, Critic
from coati.models.loss import PolicyLoss, ValueLoss
from coati.trainer.strategies import GeminiStrategy, LowLevelZeroStrategy, Strategy
from torch.optim import Adam
from colossalai.nn.optimizer import HybridAdam
from .callbacks import TrainerCallback, TrainerPerformanceEvaluator
from .detached_trainer_base import DetachedTrainer
from .lora_constructor import LoRAConstructor
from .utils import get_model_numel, get_rank, set_dist_env, state_dict_to
@ray.remote(
concurrency_groups={"buffer_length": 1, "buffer_append": 1, "buffer_sample": 1, "model_io": 1, "compute": 1}
)
class DetachedPPOTrainer(DetachedTrainer):
"""
Detached Trainer for PPO algorithm
Args:
strategy (Strategy): the strategy to use for training
model (str) : for actor / critic init
pretrained (str) : for actor / critic init
lora_rank (int) : for actor / critic init
train_batch_size (int, defaults to 8): the batch size to use for training
train_batch_size (int, defaults to 8): the batch size to use for training
buffer_limit (int, defaults to 0): the max_size limitation of replay buffer
buffer_cpu_offload (bool, defaults to True): whether to offload replay buffer to cpu
eps_clip (float, defaults to 0.2): the clip coefficient of policy loss
value_clip (float, defaults to 0.4): the clip coefficient of value loss
experience_batch_size (int, defaults to 8): the batch size to use for experience generation
max_epochs (int, defaults to 1): the number of epochs of training process
dataloader_pin_memory (bool, defaults to True): whether to pin memory for data loader
callbacks (List[Callback], defaults to []): the callbacks to call during training process
generate_kwargs (dict, optional): the kwargs to use while model generating
"""
def __init__(
self,
experience_maker_holder_name_list: List[str],
strategy_fn: Callable[[], Strategy],
model_fn: Callable[[], Tuple[Actor, Critic]],
env_info: Dict[str, str] = None,
train_batch_size: int = 8,
buffer_limit: int = 0,
eps_clip: float = 0.2,
value_clip: float = 0.4,
dataloader_pin_memory: bool = True,
callbacks: List[TrainerCallback] = [],
eval_performance: bool = False,
debug: bool = False,
update_lora_weights: bool = False,
) -> None:
# set environment variables
if env_info:
set_dist_env(env_info=env_info)
# configure strategy
self.strategy = strategy_fn()
# configure models, loss and optimizers
with self.strategy.model_init_context():
self.actor, self.critic = model_fn()
if eval_performance:
actor_numel = get_model_numel(self.actor)
critic_numel = get_model_numel(self.critic)
evaluator = TrainerPerformanceEvaluator(actor_numel, critic_numel)
callbacks = callbacks + [evaluator]
if isinstance(self.strategy, (LowLevelZeroStrategy, GeminiStrategy)):
self.actor_optim = HybridAdam(self.actor.parameters(), lr=1e-7)
self.critic_optim = HybridAdam(self.critic.parameters(), lr=1e-7)
else:
self.actor_optim = Adam(self.actor.parameters(), lr=1e-7)
self.critic_optim = Adam(self.critic.parameters(), lr=1e-7)
(self.actor, self.actor_optim), (self.critic, self.critic_optim) = self.strategy.prepare(
(self.actor, self.actor_optim), (self.critic, self.critic_optim)
)
# configure trainer
self.actor_loss_fn = PolicyLoss(eps_clip)
self.critic_loss_fn = ValueLoss(value_clip)
super().__init__(
experience_maker_holder_name_list,
train_batch_size=train_batch_size,
buffer_limit=buffer_limit,
dataloader_pin_memory=dataloader_pin_memory,
callbacks=callbacks,
debug=debug,
)
if self._debug:
print(f"[trainer{get_rank()}] will send state dict to {experience_maker_holder_name_list}")
self._update_lora_weights = update_lora_weights
@ray.method(concurrency_group="model_io")
@torch.no_grad()
def _update_remote_makers(self, fully_update: bool = False, **config):
# TODO: balance duties
if not fully_update:
config["requires_grad_only"] = True
self.update_target_holder_list()
# mark start, ensure order
tasks = []
for target_holder in self.target_holder_list:
tasks.append(target_holder.update_experience_maker.remote(chunk_start=True, fully_update=fully_update))
ray.get(tasks)
# sending loop
tasks = []
for state_dict_shard in self._get_model_state_dict_shard(self.actor, fully_update=fully_update, **config):
for target_holder in self.target_holder_list:
tasks.append(
target_holder.update_experience_maker.remote(
new_actor_state_dict=state_dict_shard,
new_actor_lora_config_dict=self._get_model_lora_config_dict(self.actor),
fully_update=fully_update,
)
)
# sending loop
for state_dict_shard in self._get_model_state_dict_shard(self.critic, fully_update=fully_update, **config):
for target_holder in self.target_holder_list:
tasks.append(
target_holder.update_experience_maker.remote(
new_critic_state_dict=state_dict_shard,
new_critic_lora_config_dict=self._get_model_lora_config_dict(self.critic),
fully_update=fully_update,
)
)
ray.get(tasks)
# mark end
for target_holder in self.target_holder_list:
target_holder.update_experience_maker.remote(chunk_end=True, fully_update=fully_update)
@ray.method(concurrency_group="compute")
def training_step(self, experience: Experience) -> Dict[str, float]:
self.actor.train()
self.critic.train()
num_actions = experience.action_mask.size(1)
action_log_probs = self.actor(experience.sequences, num_actions, attention_mask=experience.attention_mask)
actor_loss = self.actor_loss_fn(
action_log_probs, experience.action_log_probs, experience.advantages, action_mask=experience.action_mask
)
self.strategy.backward(actor_loss, self.actor, self.actor_optim)
self.strategy.optimizer_step(self.actor_optim)
self.actor_optim.zero_grad()
values = self.critic(
experience.sequences, action_mask=experience.action_mask, attention_mask=experience.attention_mask
)
critic_loss = self.critic_loss_fn(
values, experience.values, experience.reward, action_mask=experience.action_mask
)
self.strategy.backward(critic_loss, self.critic, self.critic_optim)
self.strategy.optimizer_step(self.critic_optim)
self.critic_optim.zero_grad()
return {"actor_loss": actor_loss.item(), "critic_loss": critic_loss.item()}
def strategy_save_actor(self, path: str, only_rank0: bool = False) -> None:
self.strategy.save_model(self.actor, path, only_rank0)
def strategy_save_critic(self, path: str, only_rank0: bool = False) -> None:
self.strategy.save_model(self.critic, path, only_rank0)
def strategy_save_actor_optim(self, path: str, only_rank0: bool = False) -> None:
self.strategy.save_optimizer(self.actor_optim, path, only_rank0)
def strategy_save_critic_optim(self, path: str, only_rank0: bool = False) -> None:
self.strategy.save_optimizer(self.critic_optim, path, only_rank0)
def _get_model_state_dict_shard(self, model: torch.nn.Module, fully_update=False, **config):
for state_dict in self.strategy.get_model_state_dict_shard(model, **config):
if not self._update_lora_weights or fully_update:
yield state_dict_to(state_dict)
else:
state_dict_lora, _ = LoRAConstructor.filter_state_dict_lora(state_dict)
yield state_dict_to(state_dict_lora)
def _get_model_lora_config_dict(self, model: torch.nn.Module):
if not self._update_lora_weights:
return None
unwrapped_model = self.strategy.unwrap_model(model)
return LoRAConstructor.extract_lora_config(unwrapped_model)