[pggPL]

Description

Remove unused torch::CustomClassHolder inheritance from the three C++ Userbuffers wrappers: CommOverlapHelper, CommOverlap, and CommOverlapP2P.

These classes are exposed through pybind11, with std::shared_ptr holders for the overlap classes. They are not registered as TorchBind classes and do not use the intrusive-pointer functionality supplied by CustomClassHolder. Removing the bases eliminates an unnecessary PyTorch dependency; the existing TE base classes and pybind11 bindings are retained.

Type of change

• Code refactoring

Changes

• Remove the three torch::CustomClassHolder bases in transformer_engine/pytorch/csrc/extensions.h.

Validation

• Rebuilt and linked all 34 PyTorch-extension C++ translation units from this branch on one RTX 5880 Ada, PyTorch 2.15.0a0+875d815502, CUDA 13.4. Reused the previously built common CUDA library; MPI, cuBLASMp, NVSHMEM and NCCL EP disabled.
• Four separate-process, one-rank GPU smoke tests passed: helper construction/destruction, CommOverlap, P2P AG, P2P RS. Verified TE base-class dispatch, exact BF16 buffer round-trips, communication streams, and Python ownership/release.
• Pre-commit, C++ L0 PyTorch lint (CPP_ONLY=1), license check and git diff --check passed.

Multi-GPU communication/GEMM overlap, optional backends, and the full L0 runtime suite were not run. This is not a complete stable-ABI migration. C++ consumers must rebuild against the updated class declarations.

Checklist

• Read and followed the contributing guidelines.
• Implementation complete.
• Focused validation passed.

[greptile-apps]

Confidence Score: 5/5

[Medium impact] The PR appears safe to merge.

Summary

Removes torch::CustomClassHolder inheritance from CommOverlapHelper, CommOverlap, and CommOverlapP2P.

• The Userbuffers wrappers drop an unused Torch custom-class base.

_{Reviews (2) · Last reviewed commit: "Merge branch 'main' into remove_custom_c..." · Reviewed by Greptile}

[ksivaman]

LGTM

[ksivaman]

/te-ci pytorch L1