Improve GPU-aware section in the docs #927
Open
Conversation
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
luraess
changed the title
luraess
commented
Dec 17, 2025
aklocker42
reviewed
Dec 17, 2025
docs/src/usage.md
Outdated
| > comm_loc = MPI.Comm_split_type(comm, MPI.COMM_TYPE_SHARED, rank) | ||
| > rank_loc = MPI.Comm_rank(comm_loc) | ||
| > ``` | ||
| > If using (2), one can use the default device but make sur to handle device visbility in the scheduler; for SLURM on Cray systems, this can be mostly achieved using `--gpus-per-task=1`. |
There was a problem hiding this comment.
Doesn't '--gpus-per-task' for SLURM prevent the use of GPU Peer2Peer IPC mechanisms (https://cpe.ext.hpe.com/docs/24.03/mpt/mpich/intro_mpi.html) which would have a negative impact on performance?
Member
There was a problem hiding this comment.
Yeah that's what I also remember, but perhaps Nvidia has finally fixed this?
Contributor
Author
There was a problem hiding this comment.
Thanks for pointing this out. I can make the text more generic
giordano
reviewed
Dec 17, 2025
vchuravy
reviewed
Dec 17, 2025
docs/src/usage.md
Outdated
Comment on lines
85
to
87
| Successfully running the [alltoall\_test\_cuda.jl](https://gist.github.com/luraess/0063e90cb08eb2208b7fe204bbd90ed2) | ||
| should confirm your MPI implementation to have the CUDA support enabled. Moreover, successfully running the | ||
| [alltoall\_test\_cuda\_multigpu.jl](https://gist.github.com/luraess/ed93cc09ba04fe16f63b4219c1811566) should confirm |
Member
There was a problem hiding this comment.
Can we move the files into this repository?
Contributor
Author
There was a problem hiding this comment.
Were shall one put them?
vchuravy
reviewed
Dec 17, 2025
docs/src/usage.md
Outdated
Comment on lines
103
to
108
| !!! note "Preloads" | ||
| On Cray machines, you may need to ensure the following preloads to be set in the preferences: | ||
| ``` | ||
| preloads = ["libmpi_gtl_hsa.so"] | ||
| preloads_env_switch = "MPICH_GPU_SUPPORT_ENABLED" | ||
| ``` |
vchuravy
reviewed
Dec 17, 2025
docs/src/usage.md
Outdated
| preloads_env_switch = "MPICH_GPU_SUPPORT_ENABLED" | ||
| ``` | ||
|
|
||
| !!! note "Multiple GPUs per node" |
Member
There was a problem hiding this comment.
Suggested change
| !!! note "Multiple GPUs per node" | |
| ### "Multiple GPUs per node" |
Since the text is not just on ROCM?
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
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.
Adds infos to the doc as per discussion in #924.