This will select the CPU path

-matmatmult_backend_cpu -matptap_backend_cpu

On Jul 7, 2021, at 2:43 AM, Mark Adams <mfadams@lbl.gov> wrote:

Can I turn off using cuSprarse for RAP?

On Tue, Jul 6, 2021 at 6:25 PM Barry Smith <bsmith@petsc.dev> wrote:

  Stefano has mentioned this before. He reported cuSparse matrix-matrix vector products use a very amount of memory.

On Jul 6, 2021, at 4:33 PM, Mark Adams <mfadams@lbl.gov> wrote:

I am running out of memory in GAMG. It looks like this is from the new cuSparse RAP.
I was able to run Hypre with twice as much work on the GPU as this run.
Are there parameters to tweek for this perhaps or can I disable it?

Thanks,
Mark 

   0 SNES Function norm 5.442539952302e-04
[2]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------
[2]PETSC ERROR: GPU resources unavailable
[2]PETSC ERROR: CUDA error 2 (cudaErrorMemoryAllocation) : out of memory. Reports alloc failed; this indicates the GPU has run out resources
[2]PETSC ERROR: See https://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting.
[2]PETSC ERROR: Petsc Development GIT revision: v3.15.1-569-g270a066c1e  GIT Date: 2021-07-06 03:22:54 -0700
[2]PETSC ERROR: ../ex2 on a arch-cori-gpu-opt-gcc named cgpu11 by madams Tue Jul  6 13:37:43 2021
[2]PETSC ERROR: Configure options --with-mpi-dir=/usr/common/software/sles15_cgpu/openmpi/4.0.3/gcc --with-cuda-dir=/usr/common/software/sles15_cgpu/cuda/11.1.1 --CFLAGS="   -g -DLANDAU_DIM=2 -DLANDAU_MAX_SPECI
ES=10 -DLANDAU_MAX_Q=4" --CXXFLAGS=" -g -DLANDAU_DIM=2 -DLANDAU_MAX_SPECIES=10 -DLANDAU_MAX_Q=4" --CUDAFLAGS="-g -Xcompiler -rdynamic -DLANDAU_DIM=2 -DLANDAU_MAX_SPECIES=10 -DLANDAU_MAX_Q=4" --FFLAGS="   -g " -
-COPTFLAGS="   -O3" --CXXOPTFLAGS=" -O3" --FOPTFLAGS="   -O3" --download-fblaslapack=1 --with-debugging=0 --with-mpiexec="srun -G 1" --with-cuda-gencodearch=70 --with-batch=0 --with-cuda=1 --download-p4est=1 --
download-hypre=1 --with-zlib=1 PETSC_ARCH=arch-cori-gpu-opt-gcc
[2]PETSC ERROR: #1 MatProductSymbolic_SeqAIJCUSPARSE_SeqAIJCUSPARSE() at /global/u2/m/madams/petsc/src/mat/impls/aij/seq/seqcusparse/aijcusparse.cu:2622
[2]PETSC ERROR: #2 MatProductSymbolic_ABC_Basic() at /global/u2/m/madams/petsc/src/mat/interface/matproduct.c:1159
[2]PETSC ERROR: #3 MatProductSymbolic() at /global/u2/m/madams/petsc/src/mat/interface/matproduct.c:799
[2]PETSC ERROR: #4 MatPtAP() at /global/u2/m/madams/petsc/src/mat/interface/matrix.c:9626
[2]PETSC ERROR: #5 PCGAMGCreateLevel_GAMG() at /global/u2/m/madams/petsc/src/ksp/pc/impls/gamg/gamg.c:87
[2]PETSC ERROR: #6 PCSetUp_GAMG() at /global/u2/m/madams/petsc/src/ksp/pc/impls/gamg/gamg.c:663
[2]PETSC ERROR: #7 PCSetUp() at /global/u2/m/madams/petsc/src/ksp/pc/interface/precon.c:1014
[2]PETSC ERROR: #8 KSPSetUp() at /global/u2/m/madams/petsc/src/ksp/ksp/interface/itfunc.c:406
[2]PETSC ERROR: #9 KSPSolve_Private() at /global/u2/m/madams/petsc/src/ksp/ksp/interface/itfunc.c:850
[2]PETSC ERROR: #10 KSPSolve() at /global/u2/m/madams/petsc/src/ksp/ksp/interface/itfunc.c:1084
[2]PETSC ERROR: #11 SNESSolve_NEWTONLS() at /global/u2/m/madams/petsc/src/snes/impls/ls/ls.c:225
[2]PETSC ERROR: #12 SNESSolve() at /global/u2/m/madams/petsc/src/snes/interface/snes.c:4769
[2]PETSC ERROR: #13 TSTheta_SNESSolve() at /global/u2/m/madams/petsc/src/ts/impls/implicit/theta/theta.c:185
[2]PETSC ERROR: #14 TSStep_Theta() at /global/u2/m/madams/petsc/src/ts/impls/implicit/theta/theta.c:223
[2]PETSC ERROR: #15 TSStep() at /global/u2/m/madams/petsc/src/ts/interface/ts.c:3571
[2]PETSC ERROR: #16 TSSolve() at /global/u2/m/madams/petsc/src/ts/interface/ts.c:3968
[2]PETSC ERROR: #17 main() at ex2.c:699