deepspeedai / deepspeedai/DeepSpeed

[REQUEST] Disable zero stage2 all_gather‘s bucketing

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#3,338 2 comments 0 reactions 0 assignees View on GitHub

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enhancement
Dominant language
Python
Stars
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Forks
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Avg merge
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Merged PRs (30d)
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Description

It seems that zero stage2 can never overlap all_gather with computation at the end of each step.
Bucketing the all_gather only makes it slower, and eats more GPU memory.

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by locating the ZeRO stage 2 all_gather bucketing entry point and reviewing how it is scheduled at the end of each step. Done means stage 2 can disable this bucketing, avoids the reported extra GPU memory use, and its performance is verified against the current behavior.

Written by the indexing model from the issue text.

Assessment

Tech stack
python, pytorch
Domain
distributed-systems, machine-learning, performance
Issue type
Feature
Difficulty
4/5
Estimated time
3-5 days
Activity status
Stale
Clarity
Mostly clear
Newbie friendliness
35/100

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