[FLASH-USERS] too many refinement iterations

Slavin, Jonathan jslavin at cfa.harvard.edu
Mon Sep 23 11:27:05 EDT 2019


Hi Marissa,

Thanks for sharing your experience. I'm currently letting it run, as I
mentioned, having changed the refinement criteria to remove pressure as a
refine_var. Before I try anything more I'd like to see how that turns out.
Running under gdb could take some time since even using mpi with 10 cpus on
my desktop it takes a couple hours before it starts getting into that mode
where it keeps increasing the refinement. I could, however, compile with
various checks enabled and at low optimization, which could produce useful
information.
As for the units used, here they are (note that the drag unit under
Particles/ParticlesForces and the dust unit under Particles/ParticlesMain
are units that I have written):
FLASH Units used:
   Driver/DriverMain/Split
   Grid/GridBoundaryConditions
   Grid/GridMain/paramesh/interpolation/Paramesh4/prolong
   Grid/GridMain/paramesh/interpolation/prolong
   Grid/GridMain/paramesh/paramesh4/Paramesh4dev/PM4_package/headers
   Grid/GridMain/paramesh/paramesh4/Paramesh4dev/PM4_package/mpi_source
   Grid/GridMain/paramesh/paramesh4/Paramesh4dev/PM4_package/source

 Grid/GridMain/paramesh/paramesh4/Paramesh4dev/PM4_package/utilities/multigrid
   Grid/GridParticles/GridParticlesMapFromMesh
   Grid/GridParticles/GridParticlesMapToMesh/Paramesh/MoveSieve
   Grid/GridParticles/GridParticlesMove/Sieve/BlockMatch
   Grid/GridParticles/GridParticlesMove/paramesh
   Grid/GridSolvers/HYPRE/paramesh
   IO/IOMain/hdf5/serial/PM
   IO/IOParticles/hdf5/serial
   Particles/ParticlesForces/shortRange/drag
   Particles/ParticlesInitialization
   Particles/ParticlesMain/active/dust
   Particles/ParticlesMapping/Quadratic
   Particles/ParticlesMapping/meshWeighting/MapToMesh
   PhysicalConstants/PhysicalConstantsMain
   RuntimeParameters/RuntimeParametersMain
   Simulation/SimulationMain
   flashUtilities/contiguousConversion
   flashUtilities/general
   flashUtilities/interpolation/oneDim
   flashUtilities/nameValueLL
   flashUtilities/rng
   flashUtilities/sorting/quicksort
   flashUtilities/system/memoryUsage/legacy
   monitors/Logfile/LogfileMain
   monitors/Timers/TimersMain/MPINative
   physics/Diffuse/DiffuseMain/Unsplit
   physics/Eos/EosMain/Gamma
   physics/Hydro/HydroMain/split/PPM/PPMKernel
   physics/materialProperties/Conductivity/ConductivityMain/PowerLaw

Also note that this run uses Flash 4.3.

Regards,
Jon

On Mon, Sep 23, 2019 at 11:02 AM Marissa Adams <madams at pas.rochester.edu>
wrote:

> Hi Jonathan,
>
> I've encountered something quite similar earlier this past summer. When I
> ran with AMR on a supercomputer, it would refine all the way, then crash
> via segfault. I then tried running the same executable under gdb, and it
> ran just fine. However, while running, it wouldn't even register the
> refinement! And just pushed through the time step where it refined/crashed
> as if it were a pseudo-fixed grid. It would do this, even when I asked for
> only one level of refinement, or two. I am wondering if you can run yours
> under gdb and see if it does something similar? Then perhaps we know we are
> dealing with the same "heisenbug" I've encountered.
>
> After moving back to my local machine to debug further, I sorted through
> some uninitialized variables that may have been eating at the memory and
> causing that sort of crash. I added debug -O0 and additional -W flags to
> make sure it crashed appropriataely for me to sort through the weeds. It
> was a process.... but perhaps list what units you're using and I can tell
> you if I have any cross over, and what variables I initialized that seemed
> to fix the problem.
>
> Best,
> Marissa
>
> On Mon, Sep 23, 2019 at 9:05 AM Slavin, Jonathan <jslavin at cfa.harvard.edu>
> wrote:
>
>> Hi,
>>
>> I've run into an issue with a simulation I'm running where, after
>> evolving just fine, it begins to take more and more iterations during grid
>> refinement until it fails. It's strange because I ran the same simulation
>> on a different system with the same code and same parameters and it worked
>> just fine. I did use different versions of the Intel fortran compiler and
>> the hardware (cpus) were a bit different. But in terms of the software it
>> is the same.
>> I'm currently trying again with refinement on pressure removed -
>> previously I refined on density and pressure now I'm trying just refining
>> on density.
>> If anyone has any other suggestions, I'd like to hear them.
>>
>> Thanks,
>> Jon
>>
>> --
>> Jonathan D. Slavin
>> Astrophysicist - High Energy Astrophysics Division
>> Center for Astrophysics | Harvard & Smithsonian
>> Office: (617) 496-7981 | Cell: (781) 363-0035
>> 60 Garden Street | MS 83 | Cambridge, MA 02138
>>
>>
>>

-- 
Jonathan D. Slavin
Astrophysicist - High Energy Astrophysics Division
Center for Astrophysics | Harvard & Smithsonian
Office: (617) 496-7981 | Cell: (781) 363-0035
60 Garden Street | MS 83 | Cambridge, MA 02138
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