def update(self, rollouts):
advantages = self.get_advantages(rollouts)
value_loss_epoch = 0
action_loss_epoch = 0
aux_losses_epoch = 0
dist_entropy_epoch = 0
AuxLosses.activate()
for e in range(self.ppo_epoch):
data_generator = rollouts.recurrent_generator(
advantages, self.num_mini_batch)
for sample in data_generator:
(
obs_batch,
prev_obs_batch,
recurrent_hidden_states_batch,
actions_batch,
prev_actions_batch,
value_preds_batch,
return_batch,
masks_batch,
old_action_log_probs_batch,
adv_targ,
) = sample
AuxLosses.clear()
# Reshape to do in a single forward pass for all steps
(
values,
action_log_probs,
dist_entropy,
) = self.actor_critic.evaluate_actions(
obs_batch,
prev_obs_batch,
recurrent_hidden_states_batch,
prev_actions_batch,
masks_batch,
actions_batch,
)
ratio = torch.exp(action_log_probs -
old_action_log_probs_batch)
surr1 = ratio * adv_targ
surr2 = (torch.clamp(ratio, 1.0 - self.clip_param,
1.0 + self.clip_param) * adv_targ)
action_loss = -torch.min(surr1, surr2).mean()
if self.use_clipped_value_loss:
value_pred_clipped = value_preds_batch + (
values - value_preds_batch).clamp(
-self.clip_param, self.clip_param)
value_losses = (values - return_batch).pow(2)
value_losses_clipped = (value_pred_clipped -
return_batch).pow(2)
value_loss = (
0.5 *
torch.max(value_losses, value_losses_clipped).mean())
else:
value_loss = 0.5 * (return_batch - values).pow(2).mean()
self.optimizer.zero_grad()
total_loss = (value_loss * self.value_loss_coef + action_loss -
dist_entropy * self.entropy_coef)
use_aux_loss = self.use_aux_losses
if use_aux_loss:
aux_losses = AuxLosses.reduce()
else:
aux_losses = AuxLosses.get_loss(
"information") * AuxLosses._loss_alphas["information"]
aux_losses_epoch += aux_losses.item()
total_loss = total_loss + aux_losses
self.before_backward(total_loss)
total_loss.backward()
self.after_backward(total_loss)
self.before_step()
self.optimizer.step()
self.after_step()
value_loss_epoch += value_loss.item()
action_loss_epoch += action_loss.item()
dist_entropy_epoch += dist_entropy.item()
num_updates = self.ppo_epoch * self.num_mini_batch
value_loss_epoch /= num_updates
action_loss_epoch /= num_updates
dist_entropy_epoch /= num_updates
aux_losses_epoch /= num_updates
AuxLosses.deactivate()
return (
value_loss_epoch,
action_loss_epoch,
dist_entropy_epoch,
aux_losses_epoch,
)
def train(self) -> None:
r"""Main method for DD-PPO.
Returns:
None
"""
self.local_rank, tcp_store = init_distrib_slurm(
self.config.RL.DDPPO.distrib_backend)
add_signal_handlers()
# Stores the number of workers that have finished their rollout
num_rollouts_done_store = distrib.PrefixStore("rollout_tracker",
tcp_store)
num_rollouts_done_store.set("num_done", "0")
self.world_rank = distrib.get_rank()
self.world_size = distrib.get_world_size()
self.config.defrost()
self.config.TORCH_GPU_ID = self.local_rank
self.config.SIMULATOR_GPU_ID = self.local_rank
self.config.TASK_CONFIG.TASK.POINTGOAL_WITH_EGO_PREDICTION_SENSOR.MODEL.GPU_ID = self.local_rank
# Multiply by the number of simulators to make sure they also get unique seeds
self.config.TASK_CONFIG.SEED += (self.world_rank *
self.config.NUM_PROCESSES)
self.config.freeze()
random.seed(self.config.TASK_CONFIG.SEED)
np.random.seed(self.config.TASK_CONFIG.SEED)
torch.manual_seed(self.config.TASK_CONFIG.SEED)
if torch.cuda.is_available():
self.device = torch.device("cuda", self.local_rank)
torch.cuda.set_device(self.device)
else:
self.device = torch.device("cpu")
self.envs = construct_envs(
self.config,
get_env_class(self.config.ENV_NAME),
workers_ignore_signals=True,
)
ppo_cfg = self.config.RL.PPO
if (not os.path.isdir(self.config.CHECKPOINT_FOLDER)
and self.world_rank == 0):
os.makedirs(self.config.CHECKPOINT_FOLDER)
self._setup_actor_critic_agent(ppo_cfg)
self.agent.init_distributed(find_unused_params=True)
if self.world_rank == 0:
logger.info("agent number of trainable parameters: {}".format(
sum(param.numel() for param in self.agent.parameters()
if param.requires_grad)))
observations = self.envs.reset()
batch = batch_obs(observations, device=self.device)
obs_space = self.envs.observation_spaces[0]
if self._static_encoder:
self._encoder = self.actor_critic.net.visual_encoder
obs_space = SpaceDict({
"visual_features":
spaces.Box(
low=np.finfo(np.float32).min,
high=np.finfo(np.float32).max,
shape=self._encoder.output_shape,
dtype=np.float32,
),
"prev_visual_features":
spaces.Box(
low=np.iinfo(np.uint32).min,
high=np.iinfo(np.uint32).max,
shape=self._encoder.output_shape,
dtype=np.float32,
),
**obs_space.spaces,
})
with torch.no_grad():
batch["visual_features"] = self._encoder(batch)
batch["prev_visual_features"] = torch.zeros_like(
batch["visual_features"])
rollouts = RolloutStorage(
ppo_cfg.num_steps,
self.envs.num_envs,
obs_space,
self.envs.action_spaces[0],
ppo_cfg.hidden_size,
num_recurrent_layers=self.actor_critic.net.num_recurrent_layers,
)
rollouts.to(self.device)
for sensor in rollouts.observations:
rollouts.observations[sensor][0].copy_(batch[sensor])
rollouts.previous_observations[sensor][0].copy_(
torch.zeros_like(batch[sensor]))
# batch and observations may contain shared PyTorch CUDA
# tensors. We must explicitly clear them here otherwise
# they will be kept in memory for the entire duration of training!
batch = None
observations = None
current_episode_reward = torch.zeros(self.envs.num_envs,
1,
device=self.device)
running_episode_stats = dict(
count=torch.zeros(self.envs.num_envs, 1, device=self.device),
reward=torch.zeros(self.envs.num_envs, 1, device=self.device),
)
window_episode_stats = defaultdict(
lambda: deque(maxlen=ppo_cfg.reward_window_size))
t_start = time.time()
env_time = 0
pth_time = 0
count_steps = 0
count_checkpoints = 0
start_update = 0
prev_time = 0
lr_scheduler = LambdaLR(
optimizer=self.agent.optimizer,
lr_lambda=lambda x: linear_decay(x, self.config.NUM_UPDATES),
)
interrupted_state = load_interrupted_state()
if interrupted_state is not None:
self.agent.load_state_dict(interrupted_state["state_dict"])
self.agent.optimizer.load_state_dict(
interrupted_state["optim_state"])
lr_scheduler.load_state_dict(interrupted_state["lr_sched_state"])
requeue_stats = interrupted_state["requeue_stats"]
env_time = requeue_stats["env_time"]
pth_time = requeue_stats["pth_time"]
count_steps = requeue_stats["count_steps"]
count_checkpoints = requeue_stats["count_checkpoints"]
start_update = requeue_stats["start_update"]
prev_time = requeue_stats["prev_time"]
with (TensorboardWriter(self.config.TENSORBOARD_DIR,
flush_secs=self.flush_secs)
if self.world_rank == 0 else contextlib.suppress()) as writer:
for update in range(start_update, self.config.NUM_UPDATES):
if ppo_cfg.use_linear_lr_decay:
lr_scheduler.step()
self.actor_critic.update_ib_beta(count_steps)
if ppo_cfg.use_linear_clip_decay:
self.agent.clip_param = ppo_cfg.clip_param * linear_decay(
update, self.config.NUM_UPDATES)
if EXIT.is_set():
self.envs.close()
if REQUEUE.is_set() and self.world_rank == 0:
requeue_stats = dict(
env_time=env_time,
pth_time=pth_time,
count_steps=count_steps,
count_checkpoints=count_checkpoints,
start_update=update,
prev_time=(time.time() - t_start) + prev_time,
)
save_interrupted_state(
dict(
state_dict=self.agent.state_dict(),
optim_state=self.agent.optimizer.state_dict(),
lr_sched_state=lr_scheduler.state_dict(),
config=self.config,
requeue_stats=requeue_stats,
))
requeue_job()
return
count_steps_delta = 0
self.agent.eval()
for step in range(ppo_cfg.num_steps):
(
delta_pth_time,
delta_env_time,
delta_steps,
) = self._collect_rollout_step(rollouts,
current_episode_reward,
running_episode_stats)
pth_time += delta_pth_time
env_time += delta_env_time
count_steps_delta += delta_steps
# This is where the preemption of workers happens. If a
# worker detects it will be a straggler, it preempts itself!
if (step >=
ppo_cfg.num_steps * self.SHORT_ROLLOUT_THRESHOLD
) and int(num_rollouts_done_store.get("num_done")) > (
self.config.RL.DDPPO.sync_frac * self.world_size):
break
num_rollouts_done_store.add("num_done", 1)
self.agent.train()
if self._static_encoder:
self._encoder.eval()
(
delta_pth_time,
value_loss,
action_loss,
dist_entropy,
aux_loss,
) = self._update_agent(ppo_cfg, rollouts)
pth_time += delta_pth_time
stats_ordering = list(sorted(running_episode_stats.keys()))
stats = torch.stack(
[running_episode_stats[k] for k in stats_ordering], 0)
distrib.all_reduce(stats)
for i, k in enumerate(stats_ordering):
window_episode_stats[k].append(stats[i].clone())
stats = torch.tensor(
[
value_loss,
action_loss,
aux_loss,
AuxLosses.get_loss("egomotion_error"),
AuxLosses.get_loss("information"),
0.1 * dist_entropy,
count_steps_delta,
],
device=self.device,
)
distrib.all_reduce(stats)
count_steps += stats[-1].item()
if self.world_rank == 0:
num_rollouts_done_store.set("num_done", "0")
losses = [
stats[i].item() / self.world_size
for i in range(stats.size(0) - 1)
]
deltas = {
k: ((v[-1] - v[0]).sum().item()
if len(v) > 1 else v[0].sum().item())
for k, v in window_episode_stats.items()
}
deltas["count"] = max(deltas["count"], 1.0)
print(deltas["reward"])
writer.add_scalar(
"reward",
deltas["reward"] / deltas["count"],
count_steps,
)
# Check to see if there are any metrics
# that haven't been logged yet
metrics = {
k: v / deltas["count"]
for k, v in deltas.items()
if k not in {"reward", "count"}
}
if len(metrics) > 0:
writer.add_scalars("metrics", metrics, count_steps)
writer.add_scalars(
"losses",
{
k: l
for l, k in zip(losses, [
"value", "policy", "aux", "egomotion_error",
"information", "entropy"
])
},
count_steps,
)
# log stats
if update > 0 and update % self.config.LOG_INTERVAL == 0:
logger.info("update: {}\tfps: {:.3f}\t".format(
update,
count_steps /
((time.time() - t_start) + prev_time),
))
logger.info(
"update: {}\tenv-time: {:.3f}s\tpth-time: {:.3f}s\t"
"frames: {}".format(update, env_time, pth_time,
count_steps))
logger.info("Average window size: {} {}".format(
len(window_episode_stats["count"]),
" ".join(
"{}: {:.3f}".format(k, v / deltas["count"])
for k, v in deltas.items() if k != "count"),
))
# checkpoint model
if update % self.config.CHECKPOINT_INTERVAL == 0:
self.save_checkpoint(
f"ckpt.{count_checkpoints}.pth",
dict(step=count_steps),
)
requeue_stats = dict(
env_time=env_time,
pth_time=pth_time,
count_steps=count_steps,
count_checkpoints=count_checkpoints,
start_update=update,
prev_time=(time.time() - t_start) + prev_time,
)
save_interrupted_state(
dict(
state_dict=self.agent.state_dict(),
optim_state=self.agent.optimizer.state_dict(),
lr_sched_state=lr_scheduler.state_dict(),
config=self.config,
requeue_stats=requeue_stats,
))
count_checkpoints += 1
self.envs.close()