ColossalAI/applications/Chat/coati/models/bloom/bloom_rm.py

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2023-03-28 12:25:36 +00:00
from typing import Optional
import torch.nn as nn
from transformers import BloomConfig, BloomForCausalLM, BloomModel
from ..base import RewardModel
class BLOOMRM(RewardModel):
"""
BLOOM Reward model.
Args:
pretrained (str): Pretrained model name or path.
config (BloomConfig): Model config.
checkpoint (bool): Enable gradient checkpointing.
lora_rank (int): LoRA rank.
lora_train_bias (str): LoRA bias training mode.
"""
def __init__(self,
pretrained: str = None,
config: Optional[BloomConfig] = None,
checkpoint: bool = False,
lora_rank: int = 0,
lora_train_bias: str = 'none') -> None:
if pretrained is not None:
model = BloomModel.from_pretrained(pretrained)
elif config is not None:
model = BloomModel(config)
else:
model = BloomModel(BloomConfig())
if checkpoint:
model.gradient_checkpointing_enable()
value_head = nn.Linear(model.config.hidden_size, 1)
value_head.weight.data.normal_(mean=0.0, std=1 / (model.config.hidden_size + 1))
super().__init__(model, value_head, lora_rank, lora_train_bias)