[FLASH-USERS] too many refinement iterations

[Marissa Adams]

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<mailto: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


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