Annie-Sihan-Chen commented on Jan 20 •edited by pytorch-probot bot. There is a way to prefetch data between cpu and gpu by cudaMemAdvise and cudaMemPrefetchAsync. I am wondering that is this has been intergrated in to dataloader. I found a flag prefetch_factor in dataloader constructor, not sure if it is the one.
Oct 11, 2020 · The Dataloader fetches batches so that it can perform all the preprocessing and creation on the batch on the worker process and have as few things as possible to do in the main process once the batch is ready. Why would you want workers to load samples only?
22.11.2020 · Prefetching overlaps the preprocessing and model execution of a training step This is already happening with PyTorch dataloaders. Setting num_workers=x will fork/spawn x processes that load data in parallel into a queue. See here section called "Single- and Multi-process Data Loading". I thought you are talking about device transfers?
Feb 17, 2017 · The easiest way to improve CPU utilization with the PyTorch is to use the worker process support built into Dataloader. The preprocessing that you do in using those workers should use as much native code and as little Python as possible. Use Numpy, PyTorch, OpenCV and other libraries with efficient vectorized routines that are written in C/C++.
17.02.2017 · The easiest way to improve CPU utilization with the PyTorch is to use the worker process support built into Dataloader. The preprocessing that you do in using those workers should use as much native code and as little Python as possible. Use Numpy, PyTorch, OpenCV and other libraries with efficient vectorized routines that are written in C/C++.
22.04.2020 · 5. Prefetch. IMO would be hardest to implement (though a really good idea for the project come to think about it). Basically you load data for the next iteration when your model trains. torch.utils.data.DataLoader does provide it, though there are some concerns (like
Apr 10, 2021 · However, using different prefetch_factor values did not absolutely change the used GPU memory for my pipeline. But not sure if it is due to the customized dataloader or another issue with this newer pytorch functionality (hoping to spend more time on this soon, but would appreciate any feedback if someone happens to stop by to look at this).
Jun 19, 2021 · I have a 2D array with size (20000000,500) in a txt file. Since it is too large and it cannot fit in my computer, I will have to prefetch it and train my model using pytorch. I think I will need to use dataLoader with 'prefetch_factor' parameter. Does anyone know how I would do this please? Thank you.
10.04.2021 · However, using different prefetch_factor values did not absolutely change the used GPU memory for my pipeline. But not sure if it is due to the customized dataloader or another issue with this newer pytorch functionality (hoping to spend more time on this soon, but would appreciate any feedback if someone happens to stop by to look at this).
22.11.2020 · Prefetching overlaps the preprocessing and model execution of a training step This is already happening with PyTorch dataloaders. Setting num_workers=x will fork/spawn x processes that load data in parallel into a queue. See here section called "Single- and Multi-process Data Loading". I thought you are talking about device transfers?
To avoid blocking computation code with data loading, PyTorch provides an easy switch to perform multi-process data loading by simply setting the argument num_workers to a positive integer. Single-process data loading (default) In this mode, data fetching is done in the same process a DataLoader is initialized.
class DataLoader (Generic [T_co]): r """ Data loader. Combines a dataset and a sampler, and provides an iterable over the given dataset. The :class:`~torch.utils.data.DataLoader` supports both map-style and iterable-style datasets with single- or multi-process loading, customizing loading order and optional automatic batching (collation) and memory pinning. ...