Héctor Barreiro Cabrera <[email protected]> writes: > Hello fellow PETSc users, > > Following up my previous email > <https://lists.mcs.anl.gov/pipermail/petsc-users/2020-September/042511.html>, > I managed to feed the entry data to a SeqAICUSPARSE matrix through a CUDA > kernel using the new MatCUSPARSEGetDeviceMatWrite function (thanks Barry > Smith and Mark Adams!). However, I am now facing problems when trying to > use this matrix within a SNES solver with the Eisenstat-Walker method > enabled.
Before going further, the error message makes this look like you're using -pc_type eisenstat (a "trick" to reduce the cost of Gauss-Seidel with Krylov) rather than -snes_ksp_ew (the Eisenstat-Walker method for tuning linear solver tolerances within SNES). Is this what you intend? > According to PETSc's error log, the preconditioner is failing to invert the > matrix diagonal. Specifically it says that: > [0]PETSC ERROR: Arguments are incompatible > [0]PETSC ERROR: Zero diagonal on row 0 > [0]PETSC ERROR: Configure options PETSC_ARCH=win64_vs2019_release > --with-cc="win32fe cl" --with-cxx="win32fe cl" --with-clanguage=C++ > --with-fc=0 --with-mpi=0 --with-cuda=1 --with-cudac="win32fe nvcc" > --with-cuda-dir=~/cuda --download-f2cblaslapack=1 --with-precision=single > --with-64-bit-indices=0 --with-single-library=1 --with-endian=little > --with-debugging=0 --with-x=0 --with-windows-graphics=0 > --with-shared-libraries=1 --CUDAOPTFLAGS=-O2 > > The stack trace leads to the diagonal inversion routine: > [0]PETSC ERROR: #1 MatInvertDiagonal_SeqAIJ() line 1913 in > C:\cygwin64\home\HBARRE~1\PETSC-~1\src\mat\impls\aij\seq\aij.c > [0]PETSC ERROR: #2 MatSOR_SeqAIJ() line 1944 in > C:\cygwin64\home\HBARRE~1\PETSC-~1\src\mat\impls\aij\seq\aij.c > [0]PETSC ERROR: #3 MatSOR() line 4005 in > C:\cygwin64\home\HBARRE~1\PETSC-~1\src\mat\INTERF~1\matrix.c > [0]PETSC ERROR: #4 PCPreSolve_Eisenstat() line 79 in > C:\cygwin64\home\HBARRE~1\PETSC-~1\src\ksp\pc\impls\eisens\eisen.c > [0]PETSC ERROR: #5 PCPreSolve() line 1549 in > C:\cygwin64\home\HBARRE~1\PETSC-~1\src\ksp\pc\INTERF~1\precon.c > [0]PETSC ERROR: #6 KSPSolve_Private() line 686 in > C:\cygwin64\home\HBARRE~1\PETSC-~1\src\ksp\ksp\INTERF~1\itfunc.c > [0]PETSC ERROR: #7 KSPSolve() line 889 in > C:\cygwin64\home\HBARRE~1\PETSC-~1\src\ksp\ksp\INTERF~1\itfunc.c > [0]PETSC ERROR: #8 SNESSolve_NEWTONLS() line 225 in > C:\cygwin64\home\HBARRE~1\PETSC-~1\src\snes\impls\ls\ls.c > [0]PETSC ERROR: #9 SNESSolve() line 4567 in > C:\cygwin64\home\HBARRE~1\PETSC-~1\src\snes\INTERF~1\snes.c > > I am 100% positive that the diagonal does not contain a zero entry, so my > suspicions are either that this operation is not supported on the GPU at > all (MatInvertDiagonal_SeqAIJ seems to access host-side memory) or that I > am missing some setting to make this work on the GPU. Is this correct? > > Thanks! > > Cheers, > Héctor
