[petsc-dev] asm / gasm

[Mark Adams]

Fande,

An alternative debug path that may be simpler and direct, as it works with
master:  'make runex56' in ksp/examples/tutorials in
branch mark/gamg-agg-asm.

This runs clean in valgrind (for me), I've added an ISView call to see the
data that causes the error, it runs on one processor, uses a 3^3 cell grid
(tiny), it exits cleanly with the error:

 ....
87 189
88 190
89 191
> [0]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
> [0]PETSC ERROR: Argument out of range
> [0]PETSC ERROR: Index 144 at 42 location greater than max 144
[0]PETSC ERROR: #1 VecScatterCheckIndices_Private() line 39 in
/Users/markadams/Codes/petsc/src/vec/vec/utils/vscat.c
[0]PETSC ERROR: #2 VecScatterCreate() line 1227 in
/Users/markadams/Codes/petsc/src/vec/vec/utils/vscat.c
[0]PETSC ERROR: #3 PCSetUp_GASM() line 481 in
/Users/markadams/Codes/petsc/src/ksp/pc/impls/gasm/gasm.c
  ....

This index 144 is very suspicious to me because there are 144 REAL dofs in
this test, 192 "gross" dofs, minus (48) boundary conditions. This problem
has just two aggregates with sizes 54 & 90 (=144). (I strip out the BC
vertices.)

Maybe GASM is getting confused because I do not give it domains that cover
the entire mesh (I strip out BC vertices).  GASM thinks there are 144
equations in this system when in fact there are 192.

It looks to me like GASM is working a space stripped of BCs but it is using
my indices that are in the full space.

Mark
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