pytorch

3a5427ba - Add torch.utils._content_store (#99809)

Add torch.utils._content_store (#99809) Implements a simple content-addressable store for storages (with tensors implemented as cheap references on top), enabling incremental serialization of tensors to disk, which I intend to use in the accuracy repro extractor. Check the comment at the top of torch/utils/_content_store.py for more details on the intended use case. One major piece of this PR is implementing the content hash for tensors. For our prospective use case, we may need to repeatedly hash up to 80 GB of tensor data every time we snapshot (and we may snapshot multiple times). Using a conventional cryptographic hash and hashing each snapshot would likely take on order of minutes, which seemed too slow to me. So instead, I implemented a crappy hash function that can be run on GPU. It is at least somewhat theoretically grounded: using random parameters generated by Philox, we use the standard shift-multiply and xor sum universal hash family. The hash function is a bit dorky though; instead of properly doing 160-bit math, it just runs 32-bit hash five times and cats them together. By the way, this sets the first precedent for kernel in PyTorch library which MUST be torch.compile'd to be run (in fact, this kernel does not run in eager mode because of the use of xor_sum, which doesn't actually exist in ATen.) I had to add a few more primitives to inductor, namely randint (over the entire int range) and xor_sum. Fortunately, these primitives are natively supported by Triton/C++, and so they were very easy to plumb through. xor_sum is exposed as a prim, while randint special cases on when low/high span the entire 32-bit signed integer range. Thanks to Jeff Johnson for letting me bounce ideas of him on a Saturday morning lol. Signed-off-by: Edward Z. Yang <ezyang@meta.com> Pull Request resolved: https://github.com/pytorch/pytorch/pull/99809 Approved by: https://github.com/voznesenskym