pytorch ddp mp.spawn 启动多机多卡训练
时间: 2023-10-24 12:09:19 浏览: 233
PyTorch支持使用分布式数据并行(DDP)和多进程训练(mp)来实现多机多卡训练。以下是使用PyTorch进行多机多卡训练的步骤:
1. 安装必要的软件和库。您需要安装PyTorch和Horovod(或其他分布式训练库),以便能够使用DDP和mp。
2. 编写代码。您需要编写一个PyTorch脚本,该脚本使用DDP和mp启动多机多卡训练。您可以使用以下代码片段来启动多机多卡训练:
```
import torch
import horovod.torch as hvd
from torch.nn.parallel import DistributedDataParallel
from torch.utils.data.distributed import DistributedSampler
from torchvision import datasets, transforms
# Initialize Horovod
hvd.init()
# DistributedSampler to split the dataset among the workers
train_sampler = DistributedSampler(
datasets.MNIST(
'./data',
train=True,
download=True,
transform=transforms.Compose([
transforms.ToTensor(),
transforms.Normalize((0.1307,), (0.3081,))
])
),
num_replicas=hvd.size(),
rank=hvd.rank()
)
# DataLoader to load the dataset
train_loader = torch.utils.data.DataLoader(
datasets.MNIST(
'./data',
train=True,
download=True,
transform=transforms.Compose([
transforms.ToTensor(),
transforms.Normalize((0.1307,), (0.3081,))
])
),
batch_size=64,
sampler=train_sampler
)
# Setup the model
model = ...
model = DistributedDataParallel(model)
# Define the optimizer
optimizer = ...
# An optimizer is instantiated for each worker with a copy of the model and its gradients
optimizer = hvd.DistributedOptimizer(optimizer, named_parameters=model.named_parameters())
# Train the model
for epoch in range(10):
train(epoch, model, train_loader, optimizer, hvd.rank(), hvd.size())
```
3. 启动多机多卡训练。您需要在多台计算机上启动多个进程来运行PyTorch脚本。以下是一个简单的启动脚本示例:
```
mpirun -np 4 \
-H server1:2,server2:2 \
-bind-to none -map-by slot \
-x NCCL_DEBUG=INFO -x LD_LIBRARY_PATH \
python train.py
```
上述命令将在两台计算机上启动4个进程(每台计算机上有两个进程),并将它们连接起来进行多机多卡训练。请注意,您需要将“server1”和“server2”替换为您的计算机名称或IP地址。
4. 监视训练进度。您可以使用TensorBoard等工具来监视训练进度,并在训练期间进行实时分析。
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