[petsc-dev] asm / gasm

[Mark Adams]

Barry,

ASM worked before GASM existed. I've never heard of GASM until yesterday,
other than seeing the directory in the source.  It has been so long, I
could probably hunt for a working version, but who cares, we are going to
roll back 5 years?


> > In branch mark/gamg-agg-asm in ksp ex56, 'make runex56':
>
>    I don't care about this! This is where you have tried to change from
> GASM to ASM which I told you is non-trivial.

Give me the example and command line where the GASM version in master (or
> maint) doesn't work where the error message includes ** Max-trans not
> allowed because matrix is distributed
>

Why do you want to debug GASM?  I thought we wanted to use ASM.  It is not
clear why converting from GASM to ASM is non-trivial, I could have done
this from the command line. This use aggregate-asm stuff just does what a
clever user might do.


>
>    We are not communicating very well, you jumped from stating GASM
> crashed to monkeying with ASM and now refuse to tell me how to reproduce
> the GASM crash.


I don't think you want to mess with GASM, BUT if you run ksp/ex56 with:

-pc_gamg_use_agg_gasm -mg_levels_pc_type gasm

and remove the existing -mg_levels_pc_type sor, you should see an error
that Garth and I saw (eg, appended).



> We have to start by fixing the current code to work with GASM (if it ever
> worked) and then move on to using ASM (which is just an optimization of the
> GASM usage.)
>
>
Are you sure? I am deep into debugging asm with DDT.  I can switch to GASM
by just calling the GASM set block method and use gasm in the PC, and
continue with DDT debugging.

Let me know.


16:29 master *= ~/Codes/petsc/src/ksp/ksp/examples/tutorials$ make runex56
1,4c1,85
< Linear solve converged due to CONVERGED_RTOL iterations 8
< Linear solve converged due to CONVERGED_RTOL iterations 8
< Linear solve converged due to CONVERGED_RTOL iterations 8
< [0]main |b-Ax|/|b|=1.940043e-04, |b|=4.969822e+00, emax=9.926090e-01
---
> [1]PETSC ERROR:
------------------------------------------------------------------------
> [1]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation,
probably memory access out of range
> [1]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger
> [1]PETSC ERROR: or see
http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind
> [1]PETSC ERROR: [2]PETSC ERROR:
------------------------------------------------------------------------
> [2]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation,
probably memory access out of range
> [2]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger
> [2]PETSC ERROR: or see
http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind
> [2]PETSC ERROR: or try http://valgrind.org on GNU/linux and Apple Mac OS
X to find memory corruption errors
> [6]PETSC ERROR:
------------------------------------------------------------------------
> [6]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation,
probably memory access out of range
> [6]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger
> [6]PETSC ERROR: or see
http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind
> [6]PETSC ERROR: or try http://valgrind.org on GNU/linux and Apple Mac OS
X to find memory corruption errors
> [4]PETSC ERROR:
------------------------------------------------------------------------
> [4]PETSC ERROR: Caught signal number 11 SEGV: Segmentation Violation,
probably memory access out of range
> [4]PETSC ERROR: Try option -start_in_debugger or -on_error_attach_debugger
> [4]PETSC ERROR: or see
http://www.mcs.anl.gov/petsc/documentation/faq.html#valgrind
> [4]PETSC ERROR: or try http://valgrind.org on GNU/linux and Apple Mac OS
X to find memory corruption errors
> [6]PETSC ERROR: likely location of problem given in stack below
> [6]PETSC ERROR: ---------------------  Stack Frames
------------------------------------
> [6]PETSC ERROR: Note: The EXACT line numbers in the stack are not
available,
> [6]PETSC ERROR:       INSTEAD the line number of the start of the function
> [6]PETSC ERROR:       is given.
> [6]PETSC ERROR: [6] MatGetSubMatrices_MPIAIJ_Local line 1228
/Users/markadams/Codes/petsc/src/mat/impls/aij/mpi/mpiov.c
> [6]PETSC ERROR: [6] MatGetSubMatrices_MPIAIJ line 1131
/Users/markadams/Codes/petsc/src/mat/impls/aij/mpi/mpiov.c
> [6]PETSC ERROR: [6] MatGetSubMatricesMPI_MPIXAIJ line 2163
/Users/markadams/Codes/petsc/src/mat/impls/aij/mpi/mpiov.c
> [6]PETSC ERROR: [6] MatGetSubMatricesMPI_MPIAIJ line 2418
/Users/markadams/Codes/petsc/src/mat/impls/aij/mpi/mpiov.c
> [6]PETSC ERROR: [6] MatGetSubMatricesMPI line 6805
/Users/markadams/Codes/petsc/src/mat/interface/matrix.c
> [6]PETSC ERROR: [6] PCSetUp_GASM line 357
/Users/markadams/Codes/petsc/src/ksp/pc/impls/gasm/gasm.c
> [6]PETSC ERROR: [6] PCSetUp line 930
/Users/markadams/Codes/petsc/src/ksp/pc/interface/precon.c
> [6]PETSC ERROR: [6] KSPSetUp line 305
/Users/markadams/Codes/petsc/src/ksp/ksp/interface/itfunc.c
> [6]PETSC ERROR: [6] PCSetUp_MG line 561
/Users/markadams/Codes/petsc/src/ksp/pc/impls/mg/mg.c
> [6]PETSC ERROR: --------------------- Error Message
--------------------------------------------------------------
> [6]PETSC ERROR: Signal received
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