deepspeedai / deepspeedai/DeepSpeed
[BUG] In zero3 mode, how to set nn.Linear weight (some parameters can be updated, but some cannot).
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Description
Describe the bug
For zero3, all of the parameters are partitioned, so the weight shape of nn.Linear is 0, and grad cannot be set for some dimensions of weight.
To Reproduce
from transformers import AutoModelForCausalLM, AutoTokenizer
import torch
model = AutoModelForCausalLM.from_pretrained("Qwen/Qwen-VL")
model.lm_head.weight.data[-1, :].requires_grad_(True)
RUN torchrun --nproc_per_node 8 code.py --deepspeed_config ds_config_zero3.json
Expected behavior
Code runs successfully in the mode of deepspeed zero3.
### Tasks
### Tasks
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Start with the Qwen/Qwen-VL reproduction in code.py and ds_config_zero3.json, running it with torchrun on eight processes. Trace how zero3 partitions lm_head.weight and handles the attempted requires_grad_ update on a selected row. Done means the reproduction runs successfully under DeepSpeed zero3 with the intended parameter update behavior.
Written by the indexing model from the issue text.
Assessment
- Tech stack
- python, pytorch
- Domain
- distributed-systems, machine-learning
- Issue type
- Bug
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 35/100