Safely access state dict args in load ckpt - #1957
Merged
Merged
Conversation
ananthsub
reviewed
Oct 27, 2025
Comment on lines
+1420
to
1428
| if not hasattr(ckpt_args, "tensor_model_parallel_size"): | ||
| print_rank_0("WARNING: TP size not found in checkpoint args, using 1 as default.") | ||
| if not hasattr(ckpt_args, "pipeline_model_parallel_size"): | ||
| print_rank_0("WARNING: PP size not found in checkpoint args, using 1 as default.") | ||
|
|
||
| ckpt_tp_pp = ( | ||
| state_dict['args'].tensor_model_parallel_size, | ||
| state_dict['args'].pipeline_model_parallel_size, | ||
| getattr(ckpt_args, "tensor_model_parallel_size", 1), | ||
| getattr(ckpt_args, "pipeline_model_parallel_size", 1), | ||
| ) |
Contributor
There was a problem hiding this comment.
what about instead of adding fallback values, the check for RNG states in L1443 is modified to directly check if the state dict contains args. we could safely assume that if using a converted checkpoint, we do not need to resume the rng states. the same goes for the re-run state machine check below. the point would be that we should avoid collisions with checkpoints saved with TP1/PP1
Contributor
Author
There was a problem hiding this comment.
good point. i think using 0,0 as the fallback should accomplish this. let me know if you see any issue with that.
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
4 participants
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Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be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.
What does this PR do ?
Check against checkpoint args in checkpoint loading only if they are present in the checkpoint state dict. This avoids errors when loading a checkpoint where the args are not present, eg for finetuning.
Contribution process
flowchart LR A[Pre-checks] --> B[PR Tests] subgraph Code Review/Approval C1[Expert Review] --> C2[Final Review] end B --> C1 C2 --> D[Merge]Pre-checks
Core 0.8)Code review
The following process is enforced via the CODEOWNERS file for changes into
megatron/core. For changes outside ofmegatron/core, it is up to the PR author whether or not to tag the Final Reviewer team.For MRs into `main` branch
(Step 1): Add PR label
Expert Review(Step 2): Collect the expert reviewers reviews
Expert Reviewlabel when your PR is ready for review.Final Review might get declined if these requirements are not fulfilled.
(Step 3): Final Review
Final Reviewlabel(Optional Step 4): Cherry-pick into release branch
If this PR also needs to be merged into
core_r*release branches, after this PR has been merged, selectCherry-pickto open a new PR into the release branch.For MRs into `dev` branch
The proposed review process for `dev` branch is under active discussion.MRs are mergable after one approval by either
eharper@nvidia.comorzijiey@nvidia.com.Merging your PR
Any member of core-adlr and
core-nemowill be able to merge your PR.