GPU page discuss specific restrictions of socket/gpu binding on GPU nodes.
@bdu-birhanu is already working on this.
Since Nov 4, 2025.
- Dominant language
- Python
- Stars
- 24
- Forks
- 15
- Avg merge
- 10d 3h
- Merged PRs (30d)
- 1
Description
What would you like to see added?
CPU affinity appears in gres.conf and is mapped based on hardware architecture. Affinity means that only certain physical cores are associated with each physical GPU on any GPU node for performance reasons. Cores mapped to a GPU have faster access to that GPU than cores not mapped. On the hardware, this mapping cannot be changed as it is part of the physical layout of the devices. Slurm cannot determine this on its own, so it must be instructed via gres.conf.
In practice, CPU affinity limits the ratio of cores to GPU when requesting GPUs for jobs. Setting aside QoS, if a researcher requests a single GPU and more cores than in the table below, they will potentially get multiple nodes. If they try to force a higher core count to be on a single node with --nodes=1 then the job will get stuck in queue with ReqNodeNotAvail.
The table below ignore QoS limits.
| partition | max cores:gpu from affinity | max cores for 1 gpu |
|---|---|---|
| pascal* | 14:1 | 14 |
| ampere* | 64:1 | 64 |
Contributor guide
No contributing guide indexed for this repository
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.
Assessment
This issue has not been assessed yet.