01_main-chapter-code

Appendix A: Introduction to PyTorch

Main Chapter Code

• code-part1.ipynb contains all the section A.1 to A.8 code as it appears in the chapter
• code-part2.ipynb contains all the section A.9 GPU code as it appears in the chapter
• DDP-script.py contains the script to demonstrate multi-GPU usage (note that Jupyter Notebooks only support single GPUs, so this is a script, not a notebook). You can run it as python DDP-script.py. If your machine has more than 2 GPUs, run it as CUDA_VISIBLE_DEVIVES=0,1 python DDP-script.py.
• exercise-solutions.ipynb contains the exercise solutions for this chapter

Optional Code

• DDP-script-torchrun.py is an optional version of the DDP-script.py script that runs via the PyTorch torchrun command instead of spawning and managing multiple processes ourselves via multiprocessing.spawn. The torchrun command has the advantage of automatically handling distributed initialization, including multi-node coordination, which slightly simplifies the setup process. You can use this script via torchrun --nproc_per_node=2 DDP-script-torchrun.py