[trainer] feat: ReMax support using reward model for baseline (#3780)

### What does this PR do?

> Add **concise** overview of what this PR aims to achieve or
accomplish. Reference related GitHub issues and PRs that help with the
review.

Not only limited to reward functions, we should also support using rm to
calculate the reward baseline.

### Checklist Before Starting

- [X] Search for similar PRs. Paste at least one query link here: ...
- [X] Format the PR title as `[{modules}] {type}: {description}` (This
will be checked by the CI)
- `{modules}` include `fsdp`, `megatron`, `sglang`, `vllm`, `rollout`,
`trainer`, `ci`, `training_utils`, `recipe`, `hardware`, `deployment`,
`ray`, `worker`, `single_controller`, `misc`, `perf`, `model`, `algo`,
`env`, `tool`, `ckpt`, `doc`, `data`
- If this PR involves multiple modules, separate them with `,` like
`[megatron, fsdp, doc]`
  - `{type}` is in `feat`, `fix`, `refactor`, `chore`, `test`
- If this PR breaks any API (CLI arguments, config, function signature,
etc.), add `[BREAKING]` to the beginning of the title.
  - Example: `[BREAKING][fsdp, megatron] feat: dynamic batching`

### Test

> For changes that can not be tested by CI (e.g., algorithm
implementation, new model support), validate by experiment(s) and show
results like training curve plots, evaluation results, etc.

### API and Usage Example

> Demonstrate how the API changes if any, and provide usage example(s)
if possible.

```python
# Add code snippet or script demonstrating how to use this
```

### Design & Code Changes

> Demonstrate the high-level design if this PR is complex, and list the
specific changes.

### Checklist Before Submitting

> [!IMPORTANT]
> Please check all the following items before requesting a review,
otherwise the reviewer might deprioritize this PR for review.

- [X] Read the [Contribute
Guide](https://github.com/volcengine/verl/blob/main/CONTRIBUTING.md).
- [X] Apply [pre-commit
checks](https://github.com/volcengine/verl/blob/main/CONTRIBUTING.md#code-linting-and-formatting):
`pre-commit install && pre-commit run --all-files --show-diff-on-failure
--color=always`
- [X] Add / Update [the
documentation](https://github.com/volcengine/verl/tree/main/docs).
- [X] Add unit or end-to-end test(s) to [the CI
workflow](https://github.com/volcengine/verl/tree/main/.github/workflows)
to cover all the code. If not feasible, explain why: ...
- [X] Once your PR is ready for CI, send a message in [the `ci-request`
channel](https://verl-project.slack.com/archives/C091TCESWB1) in [the
`verl` Slack
workspace](https://join.slack.com/t/verl-project/shared_invite/zt-3855yhg8g-CTkqXu~hKojPCmo7k_yXTQ).
(If not accessible, please try [the Feishu group
(飞书群)](https://applink.larkoffice.com/client/chat/chatter/add_by_link?link_token=772jd4f1-cd91-441e-a820-498c6614126a).)

Signed-off-by: Hollow Man <hollowman@opensuse.org>
This commit is contained in:
ℍ𝕠𝕝𝕝𝕠𝕨 𝕄𝕒𝕟
2025-10-17 07:07:05 +03:00
committed by GitHub
parent a80ed95e70
commit ae5d8504d4
6 changed files with 118 additions and 78 deletions

View File

@ -31,6 +31,7 @@ from verl.trainer.ppo.ray_trainer import (
compute_timing_metrics,
marked_timer,
)
from verl.trainer.ppo.reward import compute_reward
from verl.utils.metric import reduce_metrics
@ -95,14 +96,22 @@ def fit(self):
gen_baseline_output = self.actor_rollout_wg.generate_sequences(gen_baseline_batch)
batch = batch.union(gen_baseline_output)
reward_baseline_tensor = self.reward_fn(batch)
# compute reward model score on batch
rm_scores = None
if self.use_rm and "rm_scores" not in batch.batch.keys():
rm_scores = self.rm_wg.compute_rm_score(batch)
batch = batch.union(rm_scores)
reward_baseline_tensor, _ = compute_reward(batch, self.reward_fn)
reward_baseline_tensor = reward_baseline_tensor.sum(dim=-1)
batch.pop(batch_keys=list(gen_baseline_output.batch.keys()))
keys_to_pop = set(gen_baseline_output.batch.keys())
if rm_scores is not None:
keys_to_pop.update(rm_scores.batch.keys())
batch.pop(batch_keys=list(keys_to_pop))
batch.batch["reward_baselines"] = reward_baseline_tensor
del gen_baseline_batch, gen_baseline_output
del rm_scores, gen_baseline_batch, gen_baseline_output
batch.non_tensor_batch["uid"] = np.array(
[str(uuid.uuid4()) for _ in range(len(batch.batch))], dtype=object
@ -142,13 +151,13 @@ def fit(self):
# compute scores. Support both model and function-based.
# We first compute the scores using reward model. Then, we call reward_fn to combine
# the results from reward model and rule-based results.
if self.use_rm:
if self.use_rm and "rm_scores" not in batch.batch.keys():
# we first compute reward model score
reward_tensor = self.rm_wg.compute_rm_score(batch)
batch = batch.union(reward_tensor)
# we combine with rule-based rm
reward_tensor = self.reward_fn(batch)
reward_tensor, _ = compute_reward(batch, self.reward_fn)
batch.batch["token_level_scores"] = reward_tensor
# compute rewards. apply_kl_penalty if available

View File

@ -41,6 +41,7 @@ from verl.trainer.ppo.ray_trainer import (
compute_advantage,
compute_response_mask,
)
from verl.trainer.ppo.reward import compute_reward
from verl.utils.profiler import marked_timer
from verl.utils.rollout_skip import RolloutSkip
@ -152,14 +153,22 @@ class RayDAPOTrainer(RayPPOTrainer):
gen_baseline_output = self.actor_rollout_wg.generate_sequences(gen_baseline_batch)
new_batch = new_batch.union(gen_baseline_output)
reward_baseline_tensor = self.reward_fn(new_batch)
# compute reward model score on new_batch
rm_scores = None
if self.use_rm and "rm_scores" not in new_batch.batch.keys():
rm_scores = self.rm_wg.compute_rm_score(new_batch)
new_batch = new_batch.union(rm_scores)
reward_baseline_tensor, _ = compute_reward(new_batch, self.reward_fn)
reward_baseline_tensor = reward_baseline_tensor.sum(dim=-1)
new_batch.pop(batch_keys=list(gen_baseline_output.batch.keys()))
keys_to_pop = set(gen_baseline_output.batch.keys())
if rm_scores is not None:
keys_to_pop.update(rm_scores.batch.keys())
new_batch.pop(batch_keys=list(keys_to_pop))
new_batch.batch["reward_baselines"] = reward_baseline_tensor
del gen_baseline_batch, gen_baseline_output
del rm_scores, gen_baseline_batch, gen_baseline_output
new_batch.non_tensor_batch["uid"] = np.array(
[str(uuid.uuid4()) for _ in range(len(new_batch.batch))], dtype=object
@ -172,21 +181,13 @@ class RayDAPOTrainer(RayPPOTrainer):
# compute scores. Support both model and function-based.
# We first compute the scores using reward model. Then, we call reward_fn to combine
# the results from reward model and rule-based results.
if self.use_rm:
if self.use_rm and "rm_scores" not in new_batch.batch.keys():
# we first compute reward model score
reward_tensor = self.rm_wg.compute_rm_score(new_batch)
new_batch = new_batch.union(reward_tensor)
# we combine with rule-based rm
reward_extra_infos_dict: dict[str, list]
try:
reward_result = self.reward_fn(new_batch, return_dict=True)
reward_tensor = reward_result["reward_tensor"]
reward_extra_infos_dict = reward_result.get("reward_extra_info", {})
except Exception as e:
print(f"Error in reward_fn: {e}")
reward_tensor = self.reward_fn(new_batch)
reward_extra_infos_dict = {}
reward_tensor, reward_extra_infos_dict = compute_reward(new_batch, self.reward_fn)
new_batch.batch["token_level_scores"] = reward_tensor

View File

@ -39,6 +39,7 @@ from verl.trainer.ppo.ray_trainer import (
compute_advantage,
compute_response_mask,
)
from verl.trainer.ppo.reward import compute_reward
from verl.utils.profiler import simple_timer
@ -129,14 +130,22 @@ class RayEntropyTrainer(RayPPOTrainer):
gen_baseline_output = self.actor_rollout_wg.generate_sequences(gen_baseline_batch)
new_batch = new_batch.union(gen_baseline_output)
reward_baseline_tensor = self.reward_fn(new_batch)
# compute reward model score on new_batch
rm_scores = None
if self.use_rm and "rm_scores" not in new_batch.batch.keys():
rm_scores = self.rm_wg.compute_rm_score(new_batch)
new_batch = new_batch.union(rm_scores)
reward_baseline_tensor, _ = compute_reward(new_batch, self.reward_fn)
reward_baseline_tensor = reward_baseline_tensor.sum(dim=-1)
new_batch.pop(batch_keys=list(gen_baseline_output.batch.keys()))
keys_to_pop = set(gen_baseline_output.batch.keys())
if rm_scores is not None:
keys_to_pop.update(rm_scores.batch.keys())
new_batch.pop(batch_keys=list(keys_to_pop))
new_batch.batch["reward_baselines"] = reward_baseline_tensor
del gen_baseline_batch, gen_baseline_output
del rm_scores, gen_baseline_batch, gen_baseline_output
new_batch.non_tensor_batch["uid"] = np.array(
[str(uuid.uuid4()) for _ in range(len(new_batch.batch))], dtype=object
@ -149,21 +158,13 @@ class RayEntropyTrainer(RayPPOTrainer):
# compute scores. Support both model and function-based.
# We first compute the scores using reward model. Then, we call reward_fn to combine
# the results from reward model and rule-based results.
if self.use_rm:
if self.use_rm and "rm_scores" not in new_batch.batch.keys():
# we first compute reward model score
reward_tensor = self.rm_wg.compute_rm_score(new_batch)
new_batch = new_batch.union(reward_tensor)
# we combine with rule-based rm
reward_extra_infos_dict: dict[str, list]
try:
reward_result = self.reward_fn(new_batch, return_dict=True)
reward_tensor = reward_result["reward_tensor"]
reward_extra_infos_dict = reward_result["reward_extra_info"]
except Exception as e:
print(f"Error in reward_fn: {e}")
reward_tensor = self.reward_fn(new_batch)
reward_extra_infos_dict = {}
reward_tensor, reward_extra_infos_dict = compute_reward(new_batch, self.reward_fn)
new_batch.batch["token_level_scores"] = reward_tensor

View File

@ -329,6 +329,45 @@ class RayPRIMETrainer(RayPPOTrainer):
if isinstance(self.train_dataloader.dataset, RLHFDataset):
self.train_dataloader.dataset.resume_dataset_state()
def compute_reward(self, batch: DataProto, n_samples: int):
update_style = self.config.reward_model.model.get("update", "none")
reward_output_metrics = {}
if update_style == "none": # only run forward
reward_output = self.rm_wg.compute_rm_score(batch)
elif update_style == "after": # update and directly return the reward
reward_output = self.rm_wg.update_rm(batch)
elif update_style == "before": # update reward model, and then run forward
reward_output = self.rm_wg.update_rm(batch)
if "metrics" in reward_output.meta_info.keys():
reward_output_metrics = reduce_metrics(reward_output.meta_info["metrics"])
reward_output = self.rm_wg.compute_rm_score(batch)
elif update_style == "reverse": # run forward to calculate statistics, then update reward model
reward_output = self.rm_wg.compute_rm_score(batch)
# broadcast q and acc tensor to each result
bc_td = DataProto.from_dict(
tensors={
"Q_bc": reward_output.batch["q"]
.sum(dim=-1)
.view(-1, n_samples)
.unsqueeze(1)
.expand(-1, n_samples, -1)
.reshape(-1, n_samples),
"acc_bc": batch.batch["acc"]
.view(-1, n_samples)
.unsqueeze(1)
.expand(-1, n_samples, -1)
.reshape(-1, n_samples),
}
)
batch = batch.union(bc_td)
reward_output = self.rm_wg.update_rm(batch)
else:
raise NotImplementedError
return reward_output, reward_output_metrics
def fit(self):
"""
The training loop of PPO.
@ -391,10 +430,19 @@ class RayPRIMETrainer(RayPPOTrainer):
gen_baseline_output = self.actor_rollout_wg.generate_sequences(gen_baseline_batch)
batch = batch.union(gen_baseline_output)
reward_baseline_tensor = self.reward_fn(batch)
rm_scores, _ = self.compute_reward(batch, 1)
reward_baseline_tensor = rm_scores.batch.get(
"rm_scores", rm_scores.batch.get("acc_bc", None)
)
if reward_baseline_tensor is None:
raise ValueError(
"Neither 'rm_scores' nor 'acc_bc' found in reward model output for baseline."
)
reward_baseline_tensor = reward_baseline_tensor.sum(dim=-1)
batch.pop(batch_keys=list(gen_baseline_output.batch.keys()))
keys_to_pop = set(gen_baseline_output.batch.keys())
keys_to_pop.update(rm_scores.batch.keys())
batch.pop(batch_keys=list(keys_to_pop))
batch.batch["reward_baselines"] = reward_baseline_tensor
@ -450,46 +498,11 @@ class RayPRIMETrainer(RayPPOTrainer):
with simple_timer("adv", timing_raw):
if self.use_rm:
update_style = self.config.reward_model.model.get("update", "none")
if update_style == "none": # only run forward
reward_output = self.rm_wg.compute_rm_score(batch)
elif update_style == "after": # update and directly return the reward
reward_output = self.rm_wg.update_rm(batch)
elif update_style == "before": # update reward model, and then run forward
reward_output = self.rm_wg.update_rm(batch)
if "metrics" in reward_output.meta_info.keys():
reward_output_metrics = reduce_metrics(reward_output.meta_info["metrics"])
metrics.update(reward_output_metrics)
reward_output = self.rm_wg.compute_rm_score(batch)
elif (
update_style == "reverse"
): # run forward to calculate statistics, then update reward model
reward_output = self.rm_wg.compute_rm_score(batch)
# broadcast q and acc tensor to each result
bc_td = DataProto.from_dict(
tensors={
"Q_bc": reward_output.batch["q"]
.sum(dim=-1)
.view(-1, n_samples)
.unsqueeze(1)
.expand(-1, n_samples, -1)
.reshape(-1, n_samples),
"acc_bc": batch.batch["acc"]
.view(-1, n_samples)
.unsqueeze(1)
.expand(-1, n_samples, -1)
.reshape(-1, n_samples),
}
)
batch = batch.union(bc_td)
reward_output = self.rm_wg.update_rm(batch)
else:
raise NotImplementedError
reward_output, reward_output_metrics = self.compute_reward(batch, n_samples)
batch = batch.union(reward_output)
if "metrics" in reward_output.meta_info.keys():
reward_output_metrics = reduce_metrics(reward_output.meta_info["metrics"])
metrics.update(reward_output_metrics)
reward_output_metrics.update(reduce_metrics(reward_output.meta_info["metrics"]))
metrics.update(reward_output_metrics)
# compute advantages, executed on the driver process
batch = compute_advantage(

View File

@ -205,14 +205,22 @@ class RaySPPOTrainer(RayPPOTrainer):
gen_baseline_output = self.actor_rollout_wg.generate_sequences(gen_baseline_batch)
batch = batch.union(gen_baseline_output)
reward_baseline_tensor = self.reward_fn(batch)
# compute reward model score on batch
rm_scores = None
if self.use_rm and "rm_scores" not in batch.batch.keys():
rm_scores = self.rm_wg.compute_rm_score(batch)
batch = batch.union(rm_scores)
reward_baseline_tensor, _ = compute_reward(batch, self.reward_fn)
reward_baseline_tensor = reward_baseline_tensor.sum(dim=-1)
batch.pop(batch_keys=list(gen_baseline_output.batch.keys()))
keys_to_pop = set(gen_baseline_output.batch.keys())
if rm_scores is not None:
keys_to_pop.update(rm_scores.batch.keys())
batch.pop(batch_keys=list(keys_to_pop))
batch.batch["reward_baselines"] = reward_baseline_tensor
del gen_baseline_batch, gen_baseline_output
del rm_scores, gen_baseline_batch, gen_baseline_output
batch.non_tensor_batch["uid"] = np.array(
[str(uuid.uuid4()) for _ in range(len(batch.batch))], dtype=object
@ -235,7 +243,7 @@ class RaySPPOTrainer(RayPPOTrainer):
with simple_timer("reward", timing_raw):
# compute reward model score
if self.use_rm:
if self.use_rm and "rm_scores" not in batch.batch.keys():
reward_tensor = self.rm_wg.compute_rm_score(batch)
batch = batch.union(reward_tensor)

View File

@ -1065,14 +1065,22 @@ class RayPPOTrainer:
else:
gen_baseline_output = self.async_rollout_manager.generate_sequences(gen_baseline_batch)
batch = batch.union(gen_baseline_output)
reward_baseline_tensor = self.reward_fn(batch)
# compute reward model score on batch
rm_scores = None
if self.use_rm and "rm_scores" not in batch.batch.keys():
rm_scores = self.rm_wg.compute_rm_score(batch)
batch = batch.union(rm_scores)
reward_baseline_tensor, _ = compute_reward(batch, self.reward_fn)
reward_baseline_tensor = reward_baseline_tensor.sum(dim=-1)
batch.pop(batch_keys=list(gen_baseline_output.batch.keys()))
keys_to_pop = set(gen_baseline_output.batch.keys())
if rm_scores is not None:
keys_to_pop.update(rm_scores.batch.keys())
batch.pop(batch_keys=list(keys_to_pop))
batch.batch["reward_baselines"] = reward_baseline_tensor
del gen_baseline_batch, gen_baseline_output
del rm_scores, gen_baseline_batch, gen_baseline_output
# repeat to align with repeated responses in rollout
batch = batch.repeat(repeat_times=self.config.actor_rollout_ref.rollout.n, interleave=True)
batch = batch.union(gen_batch_output)