Matt, Here are matrices (double complex, 3 MB each): http://dl.dropbox.com/u/60982984/X.dat http://dl.dropbox.com/u/60982984/Y.dat Code: static char help[] = ""; int main(int argc,char **args) { Mat A,B; PetscErrorCode ierr; PetscViewer viewer; PetscScalar cone; PetscInitialize(&argc,&args,(char *)0,help); ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD,"Y.dat",FILE_MODE_READ,&viewer);CHKERRQ(ierr); ierr = MatCreate(PETSC_COMM_WORLD,&A);CHKERRQ(ierr); ierr = MatSetFromOptions(A);CHKERRQ(ierr); ierr = MatLoad(A,viewer);CHKERRQ(ierr); ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr); ierr = PetscViewerBinaryOpen(PETSC_COMM_WORLD,"X.dat",FILE_MODE_READ,&viewer);CHKERRQ(ierr); ierr = MatCreate(PETSC_COMM_WORLD,&B);CHKERRQ(ierr); ierr = MatSetFromOptions(B);CHKERRQ(ierr); ierr = MatLoad(B,viewer);CHKERRQ(ierr); ierr = PetscViewerDestroy(&viewer);CHKERRQ(ierr); cone = 1.0; ierr = MatAYPX(A,cone,B,DIFFERENT_NONZERO_PATTERN); ierr = PetscFinalize(); return 0; } It works fine if you run it with: mpirun -n 10 solveTest -mat_type aij and crashes if n > 10 Thanks. On 22.04.2012 14:51, Matthew Knepley wrote:

On Sun, Apr 22, 2012 at 8:41 AM, Alexander Grayver <[email protected] <mailto:[email protected]>> wrote:

Sorry, I don't quite get. Is this something I can avoid by doing preallocation properly or petsc issue that will be fixed?

This looks like a PETSc bug to me, but it would be nice to get input that triggers it.

Thanks,

Matt

On 20.04.2012 14:23, Jed Brown wrote:

...

On Fri, Apr 20, 2012 at 05:18, Matthew Knepley <[email protected] <mailto:[email protected]>> wrote:

Did someone intend to fix this, and then stop? MatAXPY_BasicWithPreallocation() is the same as MatAXPY_Basic().

Look how it's called. I don't know what's going on here.

ierr = MatAXPYGetPreallocation_SeqAIJ(yy->A,xx->A,nnz_d);CHKERRQ(ierr); ierr = MatAXPYGetPreallocation_SeqAIJ(yy->B,xx->B,nnz_o);CHKERRQ(ierr); ierr = MatMPIAIJSetPreallocation(B,0,nnz_d,0,nnz_o);CHKERRQ(ierr); ierr = MatAXPY_BasicWithPreallocation(B,Y,a,X,str);CHKERRQ(ierr);

-- Regards, Alexander

-- What most experimenters take for granted before they begin their experiments is infinitely more interesting than any results to which their experiments lead. -- Norbert Wiener

-- Regards, Alexander