Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
Async NCCL collectives dont block the CPU which means their futures will also get executed. This causes an issue in
manager.py
when we modify theallreduce
tensor in a callback (https://github.com/pytorch/torchft/blob/main/torchft/manager.py#L292) as the tensor may not have finishedallreduce
.The fix is to add an event after the allreduce has been
wait()
ed and then wait on this event before setting the future.Created a test to repro:
pytest torchft/manager_integ_test.py -vsk test_manager_allreduce