PyTorch 2.2: FlashAttention-v2, AOTInductor

# PyTorch 2.2 Release Notes - Highlights - Backwards Incompatible Changes - Deprecations - New Features - Improvements - Bug fixes - Performance - Documentation # Highlights We are excited to announce the release of PyTorch® 2.2! PyTorch 2.2 offers ~2x performance improvements to `scaled_dot_product_attention` via FlashAttention-v2 integration, as well as AOTInductor, a new ahead-of-time compilation and deployment tool built for non-python server-side deployments. This release also includes improved torch.compile support for Optimizers, a number of new inductor optimizations, and a new logging mechanism called TORCH_LOGS. **Please note that we are [deprecating macOS x86 support](https://github.com/pytorch/pytorch/issues/114602), and PyTorch 2.2.x will be the last version that supports macOS x64.** Along with 2.2, we are also releasing a series of updates to the PyTorch domain libraries. More details can be found in the library updates blog. This release is composed of 3,628 commits and 521 contributors since PyTorch 2.1. We want to sincerely thank our dedicated community for your contributions. As always, we encourage you to try these out and report any issues as we improve 2.2. More information about how to get started with the PyTorch 2-series can be found at our [Getting Started](https://pytorch.org/get-started/pytorch-2.0/) page. Summary: - `scaled_dot_product_attention` (SDPA) now supports FlashAttention-2, yielding around 2x speedups compared to previous versions. - PyTorch 2.2 introduces a new ahead-of-time extension of TorchInductor called AOTInductor, designed to compile and deploy PyTorch programs for non-python server-side. - `torch.distributed` supports a new abstraction for initializing and representing ProcessGroups called device_mesh. - PyTorch 2.2 ships a standardized, configurable logging mechanism called TORCH_LOGS.