What do you get for (with your openmpi install) :orte-info |grep 'MCA btl'
With cuda built openmpi - I get:
balay@petsc-gpu-01:/scratch/balay/petsc$ ./arch-linux-c-debug/bin/orte-info
|grep 'MCA btl'
MCA btl: smcuda (MCA v2.1, API v3.1, Component v4.1.6)
MCA btl: openib (MCA v2.1, API v3.1, Component v4.1.6)
MCA btl: self (MCA v2.1, API v3.1, Component v4.1.6)
MCA btl: tcp (MCA v2.1, API v3.1, Component v4.1.6)
MCA btl: vader (MCA v2.1, API v3.1, Component v4.1.6)
And without cuda:
balay@petsc-gpu-01:/scratch/balay/petsc.x$ ./arch-test/bin/orte-info | grep
'MCA btl'
MCA btl: openib (MCA v2.1, API v3.1, Component v4.1.6)
MCA btl: self (MCA v2.1, API v3.1, Component v4.1.6)
MCA btl: tcp (MCA v2.1, API v3.1, Component v4.1.6)
MCA btl: vader (MCA v2.1, API v3.1, Component v4.1.6)
i.e "smcuda" should be listed for a cuda enabled openmpi.
Its not clear if GPU-aware MPI makes a difference for all MPI impls (or
versions) - so good to verify. [its a performance issue anyway - so primarily
useful when performing timing measurements]
Satish
On Mon, 22 Sep 2025, 岳新海 wrote:
> Dear PETSc Team,
>
> I am encountering an issue when running PETSc with CUDA support on a cluster.
> When I set the vector type to VECCUDA, PETSc reports that my MPI is not
> GPU-aware. However, the MPI library (OpenMPI 4.1.5) I used to configure PETSc
> was built with the --with-cuda option enabled.
>
>
> Here are some details:
> PETSc version: 3.20.6
> MPI: OpenMPI 4.1.5, configured with --with-cuda
> GPU: RTX3090
> CUDA version: 12.1
> I have attached both my PETSc configure command and OpenMPI configure command
> for reference.
>
> My questions are:
>
>
>
>
> Even though I enabled --with-cuda in OpenMPI, why does PETSc still report
> that MPI is not GPU-aware?
>
>
>
> Are there additional steps or specific configuration flags required (either
> in OpenMPI or PETSc) to ensure GPU-aware MPI is correctly detected?
>
>
> Any guidance or suggestions would be greatly appreciated.
>
>
>
> Best regards,
>
> Xinhai Yue
>
>
>
>
>
>
>
>
>
>
>
> 岳新海
>
>
>
> 南方科技大学/学生/研究生/2023级研究生
>
>
>
> 广东省深圳市南山区学苑大道1088号
>
>
>
>
>
