Dmitry,

finally, I am able to make a simple program and reproduce the error. Since I had moved to

petsc-dev (before I used petsc-3.2), the error is a little different.

Download the program attached and run the run.sh.  You will see the output from PCASM.

There is a submatrix (submat[1] on rank 0) which has a row like

   row 1: (0, -1)  (1, 0 + 0.4 i) (4, -1)  (2, -1) 

Note that the column 2 is placed in the last and the column numbers are not in the normal order.

Following that, we can also see the error message like

   [0]PETSC ERROR: New nonzero at (1,2) caused a malloc!

You can also try with GASM, use

    mpirun -np 2 ./gasm_test -dd_type gasm -n 4 -px 1 -py 2 -sx 2 -sy 1 

which partitions the domain to 1 * 2 and mapped to the two processors, and for each processor

we further partition its local domain to 2 * 1 subdomains. 

Then, you will see that the row 1 of submat[1] on rank 1 becomes

   row 1: (0, -1)  (1, 0 + 0.4 i) (3, -1)  (6, -1) 

which is totally wrong because from the IS for this overlapping subdomain and the big matrix A,

row 1 should have non-zeros like the output from PCASM.

I guess the problem is due to that we set PCASMSetSortIndices to FALSE and something goes wrong

in asm.c and gasm.c.

Thanks!

Hui