Files
Search-R1/verl/workers/sharding_manager/fsdp_vllm.py
PeterGriffinJin 068516be64 Initial commit
2025-02-28 15:16:19 +00:00

134 lines
6.0 KiB
Python

# Copyright 2024 Bytedance Ltd. and/or its affiliates
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
import os
import logging
import torch
from torch.distributed.fsdp.fully_sharded_data_parallel import FullyShardedDataParallel as FSDP
from torch.distributed.fsdp.api import ShardingStrategy, ShardedStateDictConfig, StateDictType, FullStateDictConfig
from torch.distributed.device_mesh import DeviceMesh
from verl.third_party.vllm import LLM
from verl.third_party.vllm import parallel_state as vllm_ps
from verl import DataProto
from verl.utils.torch_functional import (broadcast_dict_tensor, allgather_dict_tensors)
from verl.utils.debug import log_gpu_memory_usage
from .base import BaseShardingManager
logger = logging.getLogger(__file__)
logger.setLevel(os.getenv('VERL_PPO_LOGGING_LEVEL', 'WARN'))
class FSDPVLLMShardingManager(BaseShardingManager):
def __init__(self,
module: FSDP,
inference_engine: LLM,
model_config,
full_params: bool = False,
device_mesh: DeviceMesh = None):
self.module = module
self.inference_engine = inference_engine
self.model_config = model_config
self.device_mesh = device_mesh
# Full params
self.full_params = full_params
if full_params:
FSDP.set_state_dict_type(self.module,
state_dict_type=StateDictType.FULL_STATE_DICT,
state_dict_config=FullStateDictConfig())
else:
FSDP.set_state_dict_type(self.module,
state_dict_type=StateDictType.SHARDED_STATE_DICT,
state_dict_config=ShardedStateDictConfig())
# Note that torch_random_states may be different on each dp rank
self.torch_random_states = torch.cuda.get_rng_state()
# get a random rng states
if self.device_mesh is not None:
gen_dp_rank = self.device_mesh['dp'].get_local_rank()
torch.cuda.manual_seed(gen_dp_rank + 1000) # make sure all tp ranks have the same random states
self.gen_random_states = torch.cuda.get_rng_state()
torch.cuda.set_rng_state(self.torch_random_states)
else:
self.gen_random_states = None
def __enter__(self):
log_gpu_memory_usage('Before state_dict() in sharding manager memory', logger=logger)
params = self.module.state_dict()
log_gpu_memory_usage('After state_dict() in sharding manager memory', logger=logger)
# Copy, not share memory
load_format = 'hf' if self.full_params else 'dtensor'
self.inference_engine.sync_model_weights(params, load_format=load_format)
log_gpu_memory_usage('After sync model weights in sharding manager', logger=logger)
del params
torch.cuda.empty_cache()
log_gpu_memory_usage('After del state_dict and empty_cache in sharding manager', logger=logger)
# TODO: offload FSDP model weights
# self.module.cpu()
# torch.cuda.empty_cache()
# if torch.distributed.get_rank() == 0:
# print(f'after model to cpu in sharding manager memory allocated: {torch.cuda.memory_allocated() / 1e9}GB, reserved: {torch.cuda.memory_reserved() / 1e9}GB')
# important: need to manually set the random states of each tp to be identical.
if self.device_mesh is not None:
self.torch_random_states = torch.cuda.get_rng_state()
torch.cuda.set_rng_state(self.gen_random_states)
def __exit__(self, exc_type, exc_value, traceback):
log_gpu_memory_usage('Before vllm offload in sharding manager', logger=logger)
self.inference_engine.offload_model_weights()
log_gpu_memory_usage('After vllm offload in sharding manager', logger=logger)
# self.module.to('cuda')
# if torch.distributed.get_rank() == 0:
# print(f'after actor module to cuda in sharding manager memory allocated: {torch.cuda.memory_allocated() / 1e9}GB, reserved: {torch.cuda.memory_reserved() / 1e9}GB')
self.module.train()
# add empty cache after each compute
torch.cuda.empty_cache()
# restore random states
if self.device_mesh is not None:
self.gen_random_states = torch.cuda.get_rng_state()
torch.cuda.set_rng_state(self.torch_random_states)
def preprocess_data(self, data: DataProto) -> DataProto:
# TODO: Current impl doesn't consider FSDP with torch micro-dp
data.batch = allgather_dict_tensors(data.batch.contiguous(),
size=vllm_ps.get_tensor_model_parallel_world_size(),
group=vllm_ps.get_tensor_model_parallel_group(),
dim=0)
return data
def postprocess_data(self, data: DataProto) -> DataProto:
# TODO: Current impl doesn't consider FSDP with torch micro-dp
broadcast_dict_tensor(data.batch,
src=vllm_ps.get_tensor_model_parallel_src_rank(),
group=vllm_ps.get_tensor_model_parallel_group())
dp_rank = torch.distributed.get_rank()
dp_size = torch.distributed.get_world_size() # not consider torch micro-dp
tp_size = vllm_ps.get_tensor_model_parallel_world_size()
if tp_size > 1:
# TODO: shall we build a micro_dp group for vllm when integrating with vLLM?
local_prompts = data.chunk(chunks=tp_size)
data = local_prompts[dp_rank % tp_size]
return data