Summary:
Same as D57688538, recreated because of GH issues
This diff introduces LocalShardsWrapper which is crucial to migrating from using ShardedTensor to DTensor in TRec state dict representation. As well as any changes needed in PT-D and ModelStore to support this.
It allows us to extend DTensor to support multiple shards on a rank as well as empty shards on a rank as needed by TRec sharding logic.
This diff also extends the support for LocalShardsWrapper to be used in conjunction with DTensor in checkpointing cases (ModelStore and DCP)
See D54375878 for how it is used.
**LocalShardsWrapper supports the following torch ops:**
+ torch.ops._c10d_functional.all_gather_into_tensor.default
+ aten._to_copy.default
+ aten.view.default
+ aten.equal.default
+ aten.detach.default
With extensibility to add more as required by use cases.
See https://docs.google.com/document/d/16Ptl50mGFJW2cljdF2HQ6FwsiA0scwbAbjx_4dhabJw/edit?usp=drivesdk for more info regarding design and approach.
NOTE: This version of LocalShardsWrapper does not support empty shards, that is added in the next diff enabling CW. D57063512
Test Plan:
` buck test mode/opt -c python.package_style=inplace aiplatform/modelstore/client/tests_gpu:dist_checkpoint_save_load_with_stateful_tests -- --print-passing-details`
`buck2 test 'fbcode//mode/dev-nosan' fbcode//torchrec/distributed/tests:test_tensor_configs -- --print-passing-details`
Sandcastle
Reviewed By: XilunWu, wanchaol
Differential Revision: D58570479
Pull Request resolved: https://github.com/pytorch/pytorch/pull/129150
Approved by: https://github.com/XilunWu
