[Dev] docs(megatron-fsdp): add Megatron-FSDP user guide

[xuwchen]

What does this PR do ?

main PR: #2396

:warning: For major changes (either in lines of code or in its impact), please make sure to first share discuss a design-doc with the team.

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

• [ ] I want this PR in a versioned release and have added the appropriate Milestone (e.g., Core 0.8)
• [ ] I have added relevant unit tests
• [ ] I have added relevant functional tests
• [ ] I have added proper typing to my code Typing guidelines
• [ ] I have added relevant documentation
• [ ] I have run the autoformatter.sh on my PR

Code review

The following process is enforced via the CODEOWNERS file for changes into megatron/core. For changes outside of megatron/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

1. Attach the Expert Review label when your PR is ready for review.
2. GitHub auto-assigns expert reviewers based on your changes. They will get notified and pick up your PR soon.

:warning: Only proceed to the next step once all reviewers have approved, merge-conflict are resolved and the CI is passing.
Final Review might get declined if these requirements are not fulfilled.

(Step 3): Final Review

1. Add Final Review label
2. GitHub auto-assigns final reviewers based on your changes. They will get notified and pick up your PR soon.

(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, select Cherry-pick to 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 [email protected] or [email protected].

Merging your PR

Any member of core-adlr and core-nemo will be able to merge your PR.

[copy-pr-bot[bot]]

This pull request requires additional validation before any workflows can run on NVIDIA's runners.

Pull request vetters can view their responsibilities here.

Contributors can view more details about this message here.

[yanring]

docs/discussions/megatron-fsdp-user-guide/example-scripts/sbatch_mfsdp_deepseek_v3.sh

Line 1:

🔴 Critical: The shebang uses a full-width exclamation mark (#！/bin/bash) instead of ASCII (#!/bin/bash). This will prevent the script from executing properly. Please replace the character with the standard ASCII !.

---

docs/discussions/megatron-fsdp-user-guide/megatron-fsdp-user-guide.md

Line 43:

Minor grammar suggestion: "This step avoids potential bubbles in the CUDA stream."

Line 51:

Typo: "douhle buffers" → "double buffers"

Line 67:

Typo: "registraion" → "registration"

Line 76:

Typo: "registraion" → "registration"

Line 88-89:

Consider adding a note clarifying where the output JSON file is saved:

This will create a `param_to_param_group_map.json` file in the `/path/to/param_to_param_group_map` directory.

---

docs/discussions/megatron-fsdp-user-guide/example-scripts/sbatch_checkpoint_convert.sh

Line 50:

The file is missing a trailing newline. Please add a newline at the end for POSIX compliance.

[BestJuly]

LGTM. Could you please help delete the Optimizing DeepSeek-V3 Training Performance on NVIDIA GB200 NVL72 part in the README.md in this PR because this has been deleted in commit 3c1b98e

[yanring]

/ok to test 5139bcda05f3f1ad554f10a7763062c0a00808c7

[BoxiangW]

Thanks Xuwen for this great documentation, can you also move it or at least link it here (code)? Not sure where is this doc/discussion being published.