feat: Implement GPU layer allocation based on memory ratio

pull/265/head
saber 2023-03-28 21:57:49 +08:00
parent c313af0639
commit 8c16099064
1 changed files with 63 additions and 12 deletions

View File

@ -1,18 +1,64 @@
import os
from typing import Dict, Tuple, Union, Optional
from typing import Dict, Tuple, Union, Optional, List
import torch
from torch.nn import Module
from transformers import AutoModel, AutoTokenizer
from transformers.tokenization_utils import PreTrainedTokenizer
def auto_configure_device_map(num_gpus: int) -> Dict[str, int]:
def calculate_per_gpu_layers(gpu_list: List[int], total_layers) -> Dict[int, int]:
# 根据每个GPU的显存大小计算每个GPU应分配的层数
# 获取每个gpu的显存大小
gpu_memory_map = {
gpu: torch.cuda.get_device_properties(gpu).total_memory
for gpu in gpu_list
}
# 计算总显存大小
total_memory = sum(gpu_memory_map.values())
# 计算每个GPU的显存比例
gpu_memory_ratios = {
gpu: memory / total_memory
for gpu, memory in gpu_memory_map.items()
}
# 计算每个 GPU 应分配的层数
per_gpu_layers = {
gpu: int(round(total_layers * ratio))
for gpu, ratio in gpu_memory_ratios.items()
}
# 修正分配误差确保总层数为total_layers
while True:
diff = total_layers - sum(per_gpu_layers.values())
if diff > 0:
gpu_with_max_memory = max(gpu_memory_ratios, key=gpu_memory_ratios.get)
per_gpu_layers[gpu_with_max_memory] += diff
elif diff < 0:
gpu_with_min_memory = min(gpu_memory_ratios, key=gpu_memory_ratios.get)
per_gpu_layers[gpu_with_min_memory] -= -diff
else:
break
return per_gpu_layers
def auto_configure_device_map(num_gpus: int, gpu_list: Optional[List[int]] = None) -> Dict[str, int]:
# transformer.word_embeddings 占用1层
# transformer.final_layernorm 和 lm_head 占用1层
# transformer.layers 占用 28 层
# 总共30层分配到num_gpus张卡上
num_trans_layers = 28
per_gpu_layers = 30 / num_gpus
if gpu_list is None:
gpu_list = list(range(num_gpus))
assert len(gpu_list) <= torch.cuda.device_count(), "分配的GPU数量超过了实际可用的GPU数量"
current_gpu_index = 0
# 获取每个gpu的承载的层数
per_gpu_layer_dict = calculate_per_gpu_layers(gpu_list, total_layers=num_trans_layers + 2)
# bugfix: 在linux中调用torch.embedding传入的weight,input不在同一device上,导致RuntimeError
# windows下 model.device 会被设置成 transformer.word_embeddings.device
@ -20,18 +66,23 @@ def auto_configure_device_map(num_gpus: int) -> Dict[str, int]:
# 在调用chat或者stream_chat时,input_ids会被放到model.device上
# 如果transformer.word_embeddings.device和model.device不同,则会导致RuntimeError
# 因此这里将transformer.word_embeddings,transformer.final_layernorm,lm_head都放到第一张卡上
device_map = {'transformer.word_embeddings': 0,
'transformer.final_layernorm': 0, 'lm_head': 0}
device_map = {'transformer.word_embeddings': gpu_list[current_gpu_index],
'transformer.final_layernorm': gpu_list[current_gpu_index], 'lm_head': gpu_list[current_gpu_index]}
used = 2
gpu_target = 0
# 分配剩余的层数
current_gpu = gpu_list[current_gpu_index]
for i in range(num_trans_layers):
if used >= per_gpu_layers:
gpu_target += 1
used = 0
assert gpu_target < num_gpus
device_map[f'transformer.layers.{i}'] = gpu_target
used += 1
if used < per_gpu_layer_dict[current_gpu]:
device_map[f"transformer.layers.{i}"] = current_gpu
used += 1
else:
# 当前 GPU 的层数已分配完,切换到下一个 GPU
current_gpu_index += 1
current_gpu = gpu_list[current_gpu_index]
device_map[f"transformer.layers.{i}"] = gpu_list[current_gpu]
used = 1
return device_map