Then Jacob has to come back and finish the baking.
Barry
> On Aug 4, 2025, at 11:27 PM, Junchao Zhang <junchao.zh...@gmail.com> wrote:
>
> CUPM is half baked, and only supports Vec and MATDENSE.
>
> --Junchao Zhang
>
>
> On Mon, Aug 4, 2025 at 7:31 PM Barry Smith <bsm...@petsc.dev
> <mailto:bsm...@petsc.dev>> wrote:
>>
>> I thought the CUPM code was intended to allow us to have common code
>> between NVIDIA and AMD?
>>
>>
>>> On Jul 31, 2025, at 11:05 AM, Junchao Zhang <junchao.zh...@gmail.com
>>> <mailto:junchao.zh...@gmail.com>> wrote:
>>>
>>> What would embarrass me more is to copy the same code to
>>> MatGetDiagonal_SeqAIJHIPSPARSE.
>>>
>>> --Junchao Zhang
>>>
>>> On Wed, Jul 30, 2025 at 1:34 PM Barry Smith <bsm...@petsc.dev
>>> <mailto:bsm...@petsc.dev>> wrote:
>>>>
>>>> We absolutely should have a MatGetDiagonal_SeqAIJCUSPARSE(). It's
>>>> somewhat embarrassing that we don't provide this.
>>>>
>>>> I have found some potential code at
>>>> https://urldefense.us/v3/__https://stackoverflow.com/questions/60311408/how-to-get-the-diagonal-of-a-sparse-matrix-in-cusparse__;!!G_uCfscf7eWS!dkLsir2oikTcYGJKRYgXdA9kTWZzg2MXrL0j0w750Ji-8wfT-NJG6B0cTCgmxasEkr_G8Fb3gHEi7xsu4I1_bao$
>>>>
>>>>
>>>> Barry
>>>>
>>>>
>>>>
>>>>
>>>>> On Jul 28, 2025, at 11:43 AM, Junchao Zhang <junchao.zh...@gmail.com
>>>>> <mailto:junchao.zh...@gmail.com>> wrote:
>>>>>
>>>>> Yes, MatGetDiagonal_SeqAIJCUSPARSE hasn't been implemented. petsc/cuda
>>>>> and petsc/kokkos backends are separate code.
>>>>> If petsc/kokkos meet your needs, then just use them. For petsc users, we
>>>>> hope it will be just a difference of extra --download-kokkos
>>>>> --download-kokkos-kernels in configuration.
>>>>>
>>>>> --Junchao Zhang
>>>>>
>>>>>
>>>>> On Mon, Jul 28, 2025 at 2:51 AM LEDAC Pierre <pierre.le...@cea.fr
>>>>> <mailto:pierre.le...@cea.fr>> wrote:
>>>>>> Hello all,
>>>>>>
>>>>>>
>>>>>>
>>>>>> We are solving with PETSc a linear system updated every time step
>>>>>> (constant stencil but coefficients changing).
>>>>>>
>>>>>>
>>>>>>
>>>>>> The matrix is preallocated once with MatSetPreallocationCOO() then
>>>>>> filled each time step with MatSetValuesCOO() and we use device pointers
>>>>>> for coo_i, coo_j, and coefficients values.
>>>>>>
>>>>>>
>>>>>>
>>>>>> It is working fine with a GMRES Ksp solver and PC Jacobi but we are
>>>>>> surprised to see that every time step, during PCSetUp,
>>>>>> MatGetDiagonal_SeqAIJ is called whereas the matrix is on the device.
>>>>>> Looking at the API, it seems there is no MatGetDiagonal_SeqAIJCUSPARSE()
>>>>>> but a MatGetDiagonal_SeqAIJKOKKOS().
>>>>>>
>>>>>>
>>>>>>
>>>>>> Does it mean we should use Kokkos backend in PETSc to have Jacobi
>>>>>> preconditioner built directly on device ? Or I am doing something wrong ?
>>>>>>
>>>>>> NB: Gmres is running well on device.
>>>>>>
>>>>>>
>>>>>>
>>>>>> I could use -ksp_reuse_preconditioner to avoid Jacobi being recreated
>>>>>> each solve on host but it increases significantly the number of
>>>>>> iterations.
>>>>>>
>>>>>>
>>>>>>
>>>>>> Thanks,
>>>>>>
>>>>>>
>>>>>>
>>>>>> <pastedImage.png>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> Pierre LEDAC
>>>>>> Commissariat à l’énergie atomique et aux énergies alternatives
>>>>>> Centre de SACLAY
>>>>>> DES/ISAS/DM2S/SGLS/LCAN
>>>>>> Bâtiment 451 – point courrier n°41
>>>>>> F-91191 Gif-sur-Yvette
>>>>>> +33 1 69 08 04 03
>>>>>> +33 6 83 42 05 79
>>>>
>>
