Changes to return correct dimensions for the MPI grid from the OpenMP subgrids

[aoloso]

Types of change(s)

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Trivial change (affects only documentation or cleanup)
• Refactor (no functional changes, no api changes)

Checklist

• Tested this change with a run of GEOSgcm
• Ran the Unit Tests (make tests)

Description

Changes were made to add attributes to the subgrids (i.e. created by dividing the MPI subdomain into smaller subdomains equal to the number of OpenMP threads) such that the correct dimensions for the MPI subdomain could be retrieved from the subgrids where ever needed.

Related Issue

use_threads set to True for openMp Issue #3274

[weiyuan-jiang]

I can confirm this fix works on Hercules with openmp

[mathomp4]

@aoloso Can you add a changelog entry for this?

[mathomp4]

Note: I did try this out with a simple AMIP run (so not exercising it probably) and it was zero-diff. So it doesn't seem to affect our way of running

[tclune]

How is the test coming along? It will be more difficult to verify the test once the fix is merged. You'll have to checkout a pre-fixed version but that version also won't have the test ...