Dear Dr. Roland,

Thanks for your insight and you are correct that I actually wanted to write back the interpolated values back onto the grid and so I was trying to access a grid function in Global mode and which I assume caused the segmentation fault as you told me. Yes, Sir I will try to debug it more and let you know if there is anything else.

Sir, So my one of the query is that:-- Is there any way, so that InterpGridArrays can use values at grid points on refinement level 0 while calculating interpolated values for grid points on refinement level 1?

Thanks for your help and time.

Thanks and regards

Aryan Sharma

On Wed, Mar 4, 2020 at 7:04 AM Roland Haas <rhaas@illinois.edu> wrote:

Hello Aryan,

> Thus, My query is:--
> Is there any way to schedule my routine in global mode so that
> InterpGridArrays can use values at grid points on level 0 while calculating
> interpolated values for grid points on refinement level 1? If I simply add
> OPTION: global or OPTIONS: global loop-local in my schedule.ccl file, the
> run crashes with a segmentation fault.
Scheduling with "OPTION: global" or "OPTION: global-late" are the correct options to use for interpolation (exotic use cases aside).

To be sure: you do not need to write back the interpolated values onto the grid, right?

A segfault in "global" mode would normally indicate that you were trying to access a grid function, since those are not accessible in global mode. However if you also get the same segfault when using loop-local then this does not seem to be the cause of the segfault.

On top of my head I am not aware of any difference in accessible memory between
"local" scheduled routines and "global loop-local" ones. If you compiled with enough debug options (and few enough -O levels) so that you get a useful backtrace, do you know the exact line in your code that causes the segfault?

Would it be possible for you to provide a demo thorn (stripped of physics, just the skeleton of the calls) that can be compiled and run demonstrate the issue (for example as an tar / zip attachment to an email)?

Yours,
Roland

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