[petsc-dev] (no subject)

[Stefano Zampini]

Junchao,

I found an issue with PetscSFReduceBegin/End. It seems that we can no
longer do (always worked before)

    ierr = PetscSFReduceBegin(sf,MPIU_INT,leaf,root,MPI_MAX);CHKERRQ(ierr);
    ierr =
PetscSFReduceBegin(sf,MPIU_INT,leaf2,root2,MPI_MAX);CHKERRQ(ierr);
    ierr = PetscSFReduceEnd(sf,MPIU_INT,leaf,root,MPI_MAX);CHKERRQ(ierr);
    ierr = PetscSFReduceEnd(sf,MPIU_INT,leaf2,root2,MPI_MAX);CHKERRQ(ierr);

You can reproduce with the currrent master
$ cd $PETSC_DIR/src/ksp/ksp/examples/tutorials
$ make ex71
$ mpiexec -n 4  ./ex71 -pde_type Elasticity -cells 7,9 -dim 2
-pc_bddc_levels 1 -pc_bddc_coarsening_ratio 2 -ksp_error_if_not_converged
-pc_bddc_monolithic -pc_bddc_use_faces
-pc_bddc_coarse_pc_bddc_corner_selection
-pc_bddc_coarse_l1_pc_bddc_corner_selection -mat_partitioning_type average
 -pc_bddc_coarse_pc_bddc_use_deluxe_scaling
-pc_bddc_coarse_sub_schurs_mat_solver_type petsc

The attached patch shows that if we instead do

    ierr = PetscSFReduceBegin(sf,MPIU_INT,leaf,root,MPI_MAX);CHKERRQ(ierr);
    ierr = PetscSFReduceEnd(sf,MPIU_INT,leaf,root,MPI_MAX);CHKERRQ(ierr);
    ierr =
PetscSFReduceBegin(sf,MPIU_INT,leaf2,root2,MPI_MAX);CHKERRQ(ierr);
    ierr = PetscSFReduceEnd(sf,MPIU_INT,leaf2,root2,MPI_MAX);CHKERRQ(ierr);

everything works properly.
I think the issue is with the SF GetPack mechanism, but I couldn't figure
out where.

-- 
Stefano
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20190722/8f55d12d/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: patch_junchao
Type: application/octet-stream
Size: 1921 bytes
Desc: not available
URL: <http://lists.mcs.anl.gov/pipermail/petsc-dev/attachments/20190722/8f55d12d/attachment.obj>