Store regrid weights

[bena-nasa]

This PR provide several things. With the regridding weights which should be a big help at large resolutions/core counts

1. The ability for MAPL_ESMFRegridder to retrieve and store the route handle weights from/to a file. Off by default. If turned on it will take the source grid dimensions, source layout, destination dimensions, destination layout, the regrids method and generate a unique file name. If the file exists, it will read rather than generate weights. If the file does not exists will generate weight as normal and then write them to a file.
2. An expanded use the "hints" option to enable item 1
3. Disable the computation of the transpose by default, this an unnecessary expense for anything other than the tangent linear model.
4. Another hint to enable the transpose in make_regridder
5. Options in the History.rc and extdata.yaml files to turn on the the write/read weights option

These weights are of course specific to a particular layout so only for a longer run where multiple executions of the model will be done and the layout doesn't change.
This should make a big difference on higher resolution runs. Even at say c180 though it still dramatically reduces the ExtData run time for a day by a factor 5 to 6

Bill claims at large core counts the writing may have issues, but since this is off by default should not harm. I will see if I can reproduce, if so though, we would have to bring up with ESMF.

Description

Related Issue

Motivation and Context

How Has This Been Tested?

Types of changes

• 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)

Checklist:

• I have tested this change with a run of GEOSgcm (if non-trivial)
• I have added one of the required labels (0 diff, 0 diff trivial, 0 diff structural, non 0-diff)
• I have updated the CHANGELOG.md accordingly following the style of Keep a Changelog

[atrayano]

We should deallocate ims and jms at the bottom of MAPL_GiedGet

[tclune]

It is unfortunate that we needed such substantial changes in ESMFRegridder, as the MAPL3G version is much cleaner. OTOH, this probably helps us to "get it right" in 3g rather than rushing to get something working in there.

[bena-nasa]

It is unfortunate that we needed such substantial changes in ESMFRegridder, as the MAPL3G version is much cleaner. OTOH, this probably helps us to "get it right" in 3g rather than rushing to get something working in there.

@tclune Yeah, but unfortunately I can't think of significantly cleaner way to do this. And this is not anywhere close to what we could do. As you say we really need to encode everything about the route handle in way so this is just scratching the surface...
Given the performance gains Bill was seeing and even what I've seen, this capability is something that I think we should support. It's just too beneficial I think throw in the towel and not pursue.

[tclune]

It is unfortunate that we needed such substantial changes in ESMFRegridder, as the MAPL3G version is much cleaner. OTOH, this probably helps us to "get it right" in 3g rather than rushing to get something working in there.

@tclune Yeah, but unfortunately I can't think of significantly cleaner way to do this.

I was not critiquing your change - just came out wrong. I meant I'd rather have treated this layer as frozen as it has been superseded. But ... as we cannot yet use MAPL3 for the full model, and we need the capability "now" ... we must implement it twice.