Flux2: Tensor tuples can cause issues for checkpointing #12777
+21
−6
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Outdated suggestions cannot be applied.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.
addresses #12776
What does this PR do?
This PR keeps the tuples, but moves the splitting from tensors into tuples of tensors to the transformer blocks, to avoid issues with checkpointing. By passing a tensor directly, torch.utils.checkpoint() identifies the tensor and saves it accordingly without running a backward through it multiple times.
This is a draft. If you agree with this change I can make it nicer. Among other things:
Who can review?
@yiyixuxu and @asomoza