在PyTorch中,实现多任务调度通常涉及到使用torch.nn.DataParallel
或torch.nn.parallel.DistributedDataParallel
来并行化模型训练,以及使用torch.utils.data.DataLoader
来管理数据加载。以下是一个简单的示例,展示了如何在PyTorch服务器上实现多任务调度:
定义多个任务模型: 首先,定义多个任务模型,每个模型负责一个特定的任务。
import torch
import torch.nn as nn
class TaskModel1(nn.Module):
def __init__(self):
super(TaskModel1, self).__init__()
self.conv1 = nn.Conv2d(1, 32, kernel_size=3)
self.conv2 = nn.Conv2d(32, 64, kernel_size=3)
self.fc1 = nn.Linear(64 * 6 * 6, 128)
self.fc2 = nn.Linear(128, 10)
def forward(self, x):
x = F.relu(self.conv1(x))
x = F.max_pool2d(x, 2)
x = F.relu(self.conv2(x))
x = F.max_pool2d(x, 2)
x = x.view(-1, 64 * 6 * 6)
x = F.relu(self.fc1(x))
x = self.fc2(x)
return x
class TaskModel2(nn.Module):
def __init__(self):
super(TaskModel2, self).__init__()
self.conv1 = nn.Conv2d(1, 32, kernel_size=3)
self.conv2 = nn.Conv2d(32, 64, kernel_size=3)
self.fc1 = nn.Linear(64 * 6 * 6, 128)
self.fc2 = nn.Linear(128, 10)
def forward(self, x):
x = F.relu(self.conv1(x))
x = F.max_pool2d(x, 2)
x = F.relu(self.conv2(x))
x = F.max_pool2d(x, 2)
x = x.view(-1, 64 * 6 * 6)
x = F.relu(self.fc1(x))
x = self.fc2(x)
return x
初始化模型: 初始化多个模型实例。
model1 = TaskModel1()
model2 = TaskModel2()
使用DataParallel进行并行化:
使用torch.nn.DataParallel
将模型并行化到多个GPU上。
if torch.cuda.device_count() > 1:
print("Using", torch.cuda.device_count(), "GPUs")
model1 = nn.DataParallel(model1)
model2 = nn.DataParallel(model2)
model1.cuda()
model2.cuda()
定义数据加载器: 定义数据加载器来加载数据。
from torchvision import datasets, transforms
transform = transforms.Compose([transforms.ToTensor()])
train_dataset1 = datasets.MNIST(root='./data', train=True, download=True, transform=transform)
train_loader1 = torch.utils.data.DataLoader(train_dataset1, batch_size=64, shuffle=True)
train_dataset2 = datasets.MNIST(root='./data', train=True, download=True, transform=transform)
train_loader2 = torch.utils.data.DataLoader(train_dataset2, batch_size=64, shuffle=True)
训练模型: 在每个任务上训练模型。
import torch.optim as optim
criterion = nn.CrossEntropyLoss()
optimizer1 = optim.SGD(model1.parameters(), lr=0.01)
optimizer2 = optim.SGD(model2.parameters(), lr=0.01)
for epoch in range(10):
for data, target in train_loader1:
data, target = data.cuda(), target.cuda()
optimizer1.zero_grad()
output = model1(data)
loss = criterion(output, target)
loss.backward()
optimizer1.step()
for data, target in train_loader2:
data, target = data.cuda(), target.cuda()
optimizer2.zero_grad()
output = model2(data)
loss = criterion(output, target)
loss.backward()
optimizer2.step()
print(f'Epoch {epoch+1}, Loss Model 1: {loss.item()}, Loss Model 2: {loss.item()}')
在这个示例中,我们定义了两个任务模型TaskModel1
和TaskModel2
,并使用torch.nn.DataParallel
将它们并行化到多个GPU上。然后,我们使用两个不同的数据加载器分别加载数据,并在每个任务上进行训练。这样可以实现多任务调度,提高训练效率。