register: restore CUDA device on deregister early exits#2215
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Jonathan-0256 wants to merge 1 commit into
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register: restore CUDA device on deregister early exits#2215Jonathan-0256 wants to merge 1 commit into
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Pull request overview
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This PR improves commDeregister to return meaningful error codes (instead of always succeeding) and corrects the CommCheck call-site name based on whether the deregister path is graph-based or not.
Changes:
- Replace unconditional
ncclSuccessreturns with an explicitretpropagated through a shared exit path. - Use
NCCLCHECKGOTOforregCleanupand add arestore:label to centralize device restoration. - Fix
CommCheckAPI name string for graph vs non-graph deregistration.
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| restore: | ||
| CUDACHECK(cudaSetDevice(saveDev)); | ||
| exit: | ||
| return ncclSuccess; | ||
| return ret; |
commDeregister() saves the caller's current CUDA device and switches to comm->cudaDev before looking up and releasing the registration handle. Two early return paths skipped restoring the saved device: invalid handles and registrations that are still referenced. This could leave callers of ncclCommDeregister() with a different current CUDA device after the API returned. Restore the saved CUDA device on all paths after switching devices, and fix the CommCheck API name used by the deregister paths. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com> Signed-off-by: Jonathan-0256 <1695830673@qq.com>
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++ @KaimingOuyang to review and mirror. CC @AddyLaddy |
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/mirror |
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Summary
commDeregister()saves the caller's current CUDA device and switches tocomm->cudaDevbefore looking up and releasing the registration handle.Two early return paths skipped restoring the saved device:
As a result,
ncclCommDeregister()could leave the caller's thread withcomm->cudaDevas the current CUDA device.This change restores the saved CUDA device on all paths after switching
devices. It also fixes the
CommCheckAPI name used by the deregister paths.Testing
git diff --check