Reduce memory usage during GWDO stats estimation #1235
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… statistics are checked to be correct
- box, box_landuse, dxm are now local variables - landuse changed to be of type I1KIND - cleanup
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Tested on Eris (GNU) with 24km grid, and Derecho (GNU) with 15km and 24km. Derecho NVHPC build and run is successful for 15km grid. |
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Tested on 5km grid as well. |
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Thanks for the additional review @mgduda! I have addressed with the last two commits. |
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Other than an update to a routine name in a comment block (as noted), I think we're in good shape. After addressing the routine name issue, feel free to rework the commit history for this PR so that it has one or a few commits with a clear and distinct purpose.
Additionally -- though it can be put off to a future PR -- it could be worth looking for simple ways of optimizing the get_box and/or get_tile_from_box_point routines.
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| end function compute_gwd_fields | ||
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| !*********************************************************************** | ||
| ! | ||
| ! function read_global_30s_topo | ||
| ! subroutine get_box_size_from_lat_lon |
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It's a minor issue, but the name of this routine has changed to get_box_size_from_lat.
A copy of #1228 with branch renamed. This PR attempts to improve the memory footprint during the computation of Gravity Wave Drag Orography statistics in the pre-processing step.
The previous approach relied on each MPI rank reading all of the topography and land use tiles, and hence would run out of memory before we could fully subscribe to all cores in a node. In the new approach, we only read in one tile at a time and when we encounter a pixel whose data is not already available in a linked list. The
get_boxsubroutine is modified to callget_tile_from_box_pointto check if the current pixel in the box is present in the linked list, and if not, it appends this tile (after reading both topo and land use data) to the head of the list.This PR also changes
box, box_landuse, dxm, nx and nyto be local variables, instead of module variables. This provides a little better readability, along with advantages of thread safety, etc.