[petsc-users] PetscSFReduceBegin can not handle MPI_CHAR?

Wed Apr 3 20:39:24 CDT 2019

  It is probably not written down anywhere (where would we write it?) nor does ./configure check it but the consensus is that PETSc now requires MPI 2.0 or later.  So developers should feel free to use any MPI 2.0 feature without guards and if you stumble across older code that still has guards/configure tests for 2.0 features those may be removed.

   Barry

  On the other hand we still require C89* code so no one would make the mistake of thinking PETSc is cutting edge ;)

  * One word -- Microsoft

> On Apr 3, 2019, at 3:39 AM, Lisandro Dalcin via petsc-users <petsc-users at mcs.anl.gov> wrote:
> 
> IIRC, MPI_CHAR is for ASCII text data. Also, remember that in C the signedness of plain `char` is implementation (or platform?) dependent.
>  I'm not sure MPI_Reduce() is supposed to / should  handle MPI_CHAR, you should use MPI_{SIGNED|UNSIGNED}_CHAR for that. Note however that MPI_SIGNED_CHAR is from MPI 2.0.
> 
> On Wed, 3 Apr 2019 at 07:01, Fande Kong via petsc-users <petsc-users at mcs.anl.gov> wrote:
> Hi All,
> 
> There were some error messages when using PetscSFReduceBegin with MPI_CHAR. 
> 
> ierr = PetscSFReduceBegin(ptap->sf,MPI_CHAR,rmtspace,space,MPI_SUM);CHKERRQ(ierr);
> 
> 
> My question would be: Does PetscSFReduceBegin suppose work with MPI_CHAR? If not, should we document somewhere?
> 
> Thanks
> 
> Fande,
> 
> 
> [0]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------
> [0]PETSC ERROR: No support for this operation for this object type
> [0]PETSC ERROR: No support for type size not divisible by 4
> [0]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting.
> [0]PETSC ERROR: Petsc Development GIT revision: v3.10.4-1989-gd816d1587e  GIT Date: 2019-04-02 17:37:18 -0600
> [0]PETSC ERROR: [1]PETSC ERROR: --------------------- Error Message --------------------------------------------------------------
> [1]PETSC ERROR: No support for this operation for this object type
> [1]PETSC ERROR: No support for type size not divisible by 4
> [1]PETSC ERROR: See http://www.mcs.anl.gov/petsc/documentation/faq.html for trouble shooting.
> [1]PETSC ERROR: Petsc Development GIT revision: v3.10.4-1989-gd816d1587e  GIT Date: 2019-04-02 17:37:18 -0600
> [1]PETSC ERROR: ./ex90 on a arch-linux2-c-dbg-feature-ptap-all-at-once named fn605731.local by kongf Tue Apr  2 21:48:41 2019
> [1]PETSC ERROR: Configure options --download-hypre=1 --with-debugging=yes --with-shared-libraries=1 --download-fblaslapack=1 --download-metis=1 --download-parmetis=1 --download-superlu_dist=1 PETSC_ARCH=arch-linux2-c-dbg-feature-ptap-all-at-once --download-ptscotch --download-party --download-chaco --with-cxx-dialect=C++11
> [1]PETSC ERROR: #1 PetscSFBasicPackTypeSetup() line 678 in /Users/kongf/projects/petsc/src/vec/is/sf/impls/basic/sfbasic.c
> [1]PETSC ERROR: #2 PetscSFBasicGetPack() line 804 in /Users/kongf/projects/petsc/src/vec/is/sf/impls/basic/sfbasic.c
> [1]PETSC ERROR: #3 PetscSFReduceBegin_Basic() line 1024 in /Users/kongf/projects/petsc/src/vec/is/sf/impls/basic/sfbasic.c
> ./ex90 on a arch-linux2-c-dbg-feature-ptap-all-at-once named fn605731.local by kongf Tue Apr  2 21:48:41 2019
> [0]PETSC ERROR: Configure options --download-hypre=1 --with-debugging=yes --with-shared-libraries=1 --download-fblaslapack=1 --download-metis=1 --download-parmetis=1 --download-superlu_dist=1 PETSC_ARCH=arch-linux2-c-dbg-feature-ptap-all-at-once --download-ptscotch --download-party --download-chaco --with-cxx-dialect=C++11
> [0]PETSC ERROR: #1 PetscSFBasicPackTypeSetup() line 678 in /Users/kongf/projects/petsc/src/vec/is/sf/impls/basic/sfbasic.c
> [0]PETSC ERROR: #2 PetscSFBasicGetPack() line 804 in /Users/kongf/projects/petsc/src/vec/is/sf/impls/basic/sfbasic.c
> [0]PETSC ERROR: #3 PetscSFReduceBegin_Basic() line 1024 in /Users/kongf/projects/petsc/src/vec/is/sf/impls/basic/sfbasic.c
> [0]PETSC ERROR: #4 PetscSFReduceBegin() line 1208 in /Users/kongf/projects/petsc/src/vec/is/sf/interface/sf.c
> [0]PETSC ERROR: #5 MatPtAPNumeric_MPIAIJ_MPIAIJ_allatonce() line 850 in /Users/kongf/projects/petsc/src/mat/impls/aij/mpi/mpiptap.c
> [0]PETSC ERROR: #6 MatPtAP_MPIAIJ_MPIAIJ() line 202 in /Users/kongf/projects/petsc/src/mat/impls/aij/mpi/mpiptap.c
> [0]PETSC ERROR: #7 MatPtAP() line 9429 in /Users/kongf/projects/petsc/src/mat/interface/matrix.c
> [0]PETSC ERROR: #8 main() line 58 in /Users/kongf/projects/petsc/src/mat/examples/tests/ex90.c
> [0]PETSC ERROR: PETSc Option Table entries:
> [0]PETSC ERROR: -matptap_via allatonce
> [0]PETSC ERROR: ----------------End of Error Message -------send entire error message to petsc-maint at mcs.anl.gov----------
> [1]PETSC ERROR: #4 PetscSFReduceBegin() line 1208 in /Users/kongf/projects/petsc/src/vec/is/sf/interface/sf.c
> [1]PETSC ERROR: #5 MatPtAPNumeric_MPIAIJ_MPIAIJ_allatonce() line 850 in /Users/kongf/projects/petsc/src/mat/impls/aij/mpi/mpiptap.c
> [1]PETSC ERROR: #6 MatPtAP_MPIAIJ_MPIAIJ() line 202 in /Users/kongf/projects/petsc/src/mat/impls/aij/mpi/mpiptap.c
> [1]PETSC ERROR: #7 MatPtAP() line 9429 in /Users/kongf/projects/petsc/src/mat/interface/matrix.c
> [1]PETSC ERROR: #8 main() line 58 in /Users/kongf/projects/petsc/src/mat/examples/tests/ex90.c
> [1]PETSC ERROR: PETSc Option Table entries:
> [1]PETSC ERROR: -matptap_via allatonce
> [1]PETSC ERROR: ----------------End of Error Message -------send entire error message to petsc-maint at mcs.anl.gov----------
> --------------------------------------------------------------------------
> MPI_ABORT was invoked on rank 1 in communicator MPI_COMM_WORLD
> with errorcode 56.
> 
> NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
> You may or may not see output from other processes, depending on
> exactly when Open MPI kills them.
> --------------------------------------------------------------------------
> [fn605731.local:78133] 1 more process has sent help message help-mpi-api.txt / mpi-abort
> [fn605731.local:78133] Set MCA parameter "orte_base_help_aggregate" to 0 to see all help / error messages
> 
> 
> -- 
> Lisandro Dalcin
> ============
> Research Scientist
> Extreme Computing Research Center (ECRC)
> King Abdullah University of Science and Technology (KAUST)
> http://ecrc.kaust.edu.sa/