hiyouga de0ebab464 fix #2189
Former-commit-id: b3d81b229d376671e1c12229aeb487b0d84f2548
2024-02-04 00:47:37 +08:00

60 lines
2.3 KiB
Python

import json
from contextlib import nullcontext
from typing import TYPE_CHECKING, Dict, List, Literal, Optional
import torch
from transformers.integrations import is_deepspeed_zero3_enabled
from ...extras.packages import is_requests_available
if TYPE_CHECKING:
from transformers import PreTrainedModel
from trl import AutoModelForCausalLMWithValueHead
if is_requests_available():
import requests
def get_rewards_from_server(server_url: str, messages: List[str]) -> List[torch.Tensor]:
headers = {"Content-Type": "application/json"}
payload = {"model": "model", "messages": messages}
response = requests.post(server_url, json=payload, headers=headers)
rewards = json.loads(response.text)["scores"]
return torch.Tensor(rewards)
def replace_model(model: "AutoModelForCausalLMWithValueHead", target: Literal["default", "reward"]) -> None:
if is_deepspeed_zero3_enabled():
import deepspeed # type: ignore
params = [model.v_head.summary.weight, model.v_head.summary.bias]
context_maybe_zero3 = deepspeed.zero.GatheredParameters(params, modifier_rank=0)
else:
context_maybe_zero3 = nullcontext()
with context_maybe_zero3:
if target == "reward": # save default head temporarily
setattr(model, "default_head_weight", model.v_head.summary.weight.data.detach().clone())
setattr(model, "default_head_bias", model.v_head.summary.bias.data.detach().clone())
model.pretrained_model.set_adapter(target) # set the LoRA adapter to be active
model.v_head.summary.weight.data = model.get_buffer("{}_head_weight".format(target)).detach().clone()
model.v_head.summary.bias.data = model.get_buffer("{}_head_bias".format(target)).detach().clone()
def dump_layernorm(model: "PreTrainedModel") -> Dict[str, torch.Tensor]:
layer_norm_params = {}
for name, param in model.named_parameters():
if param.data.dtype == torch.float32:
layer_norm_params[name] = param.data.detach().clone()
param.data = param.data.to(model.config.torch_dtype)
return layer_norm_params
def restore_layernorm(model: "PreTrainedModel", layernorm_params: Optional[Dict[str, torch.Tensor]] = None) -> None:
for name, param in model.named_parameters():
if name in layernorm_params:
param.data = layernorm_params[name]