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VBTI-development/onedl-mmengine

 
 

What's New

The VBTI development team is reviving MMLabs code, making it work with newer pytorch versions and fixing bugs. We are only a small team, so your help is appreciated. Also: since we don't speak or read Chinese, Chinese docs are deleted.

v0.10.6 was released on 2025-01-13.

Highlights:

  • Support custom artifact_location in MLflowVisBackend #1505
  • Enable exclude_frozen_parameters for DeepSpeedEngine._zero3_consolidated_16bit_state_dict #1517

Read Changelog for more details.

Introduction

MMEngine is a foundational library for training deep learning models based on PyTorch. It serves as the training engine of all OpenMMLab codebases, which support hundreds of algorithms in various research areas. Moreover, MMEngine is also generic to be applied to non-OpenMMLab projects. Its highlights are as follows:

Integrate mainstream large-scale model training frameworks

Supports a variety of training strategies

Provides a user-friendly configuration system

Covers mainstream training monitoring platforms

Installation

Supported PyTorch Versions
MMEngine PyTorch Python
main >=1.6 <=2.1 >=3.10, <=3.11

Before installing MMEngine, please ensure that PyTorch has been successfully installed following the official guide.

Install MMEngine

pip install -U onedl-mim
mim install onedl-mmengine

Verify the installation

python -c 'from mmengine.utils.dl_utils import collect_env;print(collect_env())'

Get Started

Taking the training of a ResNet-50 model on the CIFAR-10 dataset as an example, we will use MMEngine to build a complete, configurable training and validation process in less than 80 lines of code.

Build Models

First, we need to define a model which 1) inherits from BaseModel and 2) accepts an additional argument mode in the forward method, in addition to those arguments related to the dataset.

  • During training, the value of mode is "loss", and the forward method should return a dict containing the key "loss".
  • During validation, the value of mode is "predict", and the forward method should return results containing both predictions and labels.
import torch.nn.functional as F
import torchvision
from mmengine.model import BaseModel

class MMResNet50(BaseModel):
    def __init__(self):
        super().__init__()
        self.resnet = torchvision.models.resnet50()

    def forward(self, imgs, labels, mode):
        x = self.resnet(imgs)
        if mode == 'loss':
            return {'loss': F.cross_entropy(x, labels)}
        elif mode == 'predict':
            return x, labels
Build Datasets

Next, we need to create Datasets and DataLoaders for training and validation. In this case, we simply use built-in datasets supported in TorchVision.

import torchvision.transforms as transforms
from torch.utils.data import DataLoader

norm_cfg = dict(mean=[0.491, 0.482, 0.447], std=[0.202, 0.199, 0.201])
train_dataloader = DataLoader(batch_size=32,
                              shuffle=True,
                              dataset=torchvision.datasets.CIFAR10(
                                  'data/cifar10',
                                  train=True,
                                  download=True,
                                  transform=transforms.Compose([
                                      transforms.RandomCrop(32, padding=4),
                                      transforms.RandomHorizontalFlip(),
                                      transforms.ToTensor(),
                                      transforms.Normalize(**norm_cfg)
                                  ])))
val_dataloader = DataLoader(batch_size=32,
                            shuffle=False,
                            dataset=torchvision.datasets.CIFAR10(
                                'data/cifar10',
                                train=False,
                                download=True,
                                transform=transforms.Compose([
                                    transforms.ToTensor(),
                                    transforms.Normalize(**norm_cfg)
                                ])))
Build Metrics

To validate and test the model, we need to define a Metric called accuracy to evaluate the model. This metric needs to inherit from BaseMetric and implements the process and compute_metrics methods.

from mmengine.evaluator import BaseMetric

class Accuracy(BaseMetric):
    def process(self, data_batch, data_samples):
        score, gt = data_samples
        # Save the results of a batch to `self.results`
        self.results.append({
            'batch_size': len(gt),
            'correct': (score.argmax(dim=1) == gt).sum().cpu(),
        })
    def compute_metrics(self, results):
        total_correct = sum(item['correct'] for item in results)
        total_size = sum(item['batch_size'] for item in results)
        # Returns a dictionary with the results of the evaluated metrics,
        # where the key is the name of the metric
        return dict(accuracy=100 * total_correct / total_size)
Build a Runner

Finally, we can construct a Runner with previously defined Model, DataLoader, and Metrics, with some other configs, as shown below.

from torch.optim import SGD
from mmengine.runner import Runner

runner = Runner(
    model=MMResNet50(),
    work_dir='./work_dir',
    train_dataloader=train_dataloader,
    # a wrapper to execute back propagation and gradient update, etc.
    optim_wrapper=dict(optimizer=dict(type=SGD, lr=0.001, momentum=0.9)),
    # set some training configs like epochs
    train_cfg=dict(by_epoch=True, max_epochs=5, val_interval=1),
    val_dataloader=val_dataloader,
    val_cfg=dict(),
    val_evaluator=dict(type=Accuracy),
)
Launch Training
runner.train()

Learn More

Tutorials
Advanced tutorials
Examples
Common Usage
Design
Migration guide

Contributing

We appreciate all contributions to improve MMEngine. Please refer to CONTRIBUTING.md for the contributing guideline.

Citation

If you find this project useful in your research, please consider cite:

@article{mmengine2022,
  title   = {{OneDL-MMEngine}: Foundational Library for Training Deep Learning Models},
  author  = {OneDL-MMEngine Contributors},
  howpublished = {\url{https://github.com/vbti-development/onedl-mmengine}},
  year={2022}
}

License

This project is released under the Apache 2.0 license.

Projects in VBTI-development

  • MMEngine: Foundational library for training deep learning models.
  • MMCV: Foundational library for computer vision.
  • MMPreTrain: Pre-training toolbox and benchmark.
  • MMDetection: Detection toolbox and benchmark.
  • MMRotate: Rotated object detection toolbox and benchmark.
  • MMSegmentation: Semantic segmentation toolbox and benchmark.
  • MMDeploy: Model deployment framework.
  • MIM: MIM installs VBTI packages.

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