pytorch

2ce9513b - AccumulateGrad: ensure sparse tensor indices and values refcount is always 1 (#34559)

AccumulateGrad: ensure sparse tensor indices and values refcount is always 1 (#34559) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/34559 We check the use_count for indices and values when we avoid a clone for sparse tensors. The sparse tensor grad itself might have a higher refcount due to DDP hooks/dist autograd structures holding refs, but the indices and values inside the sparse tensor should always have a refcount of 1. ghstack-source-id: 99900534 Test Plan: waitforbuildbot Differential Revision: D20375239 fbshipit-source-id: 6a654549d13071ab3451cef94259caf7627b575c