Version 6 (modified by epico, 6 months ago) (diff)

Name and subject of the action

Last edition: 11/29/19 22:57:59 by epico

The PI is responsible to closely follow the progress of the action, and especially to contact NEMO project manager if the delay on preview (or review) are longer than the 2 weeks expected.

  1. Summary
  2. Preview
  3. Tests
  4. Review

Summary

Analysis of scalability improvement using MPI3 new communications (e.g. collective neighbours communications) instead of point to point communications.

ticket: #2011

Preview

Mirek Andrejczuk

Plan outlined in ticket #2011 is OK. Most likely changes to the code will be limited to LBC/lib_mpp.F90. 
I'm happy to test the changes in MO operational configurations. May be worth considering implementation 
in which changing the number of halo points is easy.

Tests

Once the development is done, the PI should complete the tests section below and after ask the reviewers to start their review.

This part should contain the detailed results of SETTE tests (restartability and reproducibility for each of the reference configuration) and detailed results of restartability and reproducibility when the option is activated on specified configurations used for this test

Regular checks:

  • Can this change be shown to produce expected impact (option activated)?
  • Can this change be shown to have a null impact (option not activated)?
  • Results of the required bit comparability tests been run: are there no differences when activating the development?
  • If some differences appear, is reason for the change valid/understood?
  • If some differences appear, is the impact as expected on model configurations?
  • Is this change expected to preserve all diagnostics?
  • If no, is reason for the change valid/understood?
  • Are there significant changes in run time/memory?

The change improves the communication time. Preliminary tests show an improvement within a range of 18%-32% on the GYRE_PISCES configuration (with nn_GYRE=200), depending on the allocated number of cores

Results of the required bit comparability tests: No differences between outputs

This change preserves all diagnostics

Review

A successful review is needed to schedule the merge of this development into the future NEMO release during next Merge Party (usually in November).

Assessments:

  • Is the proposed methodology now implemented?
  • Are the code changes in agreement with the flowchart defined at preview step?
  • Are the code changes in agreement with list of routines and variables as proposed at preview step?
    If, not, are the discrepancies acceptable?
  • Is the in-line documentation accurate and sufficient?
  • Do the code changes comply with NEMO coding standards?
  • Is the development documented with sufficient details for others to understand the impact of the change?
  • Is the project literature (manual, guide, web, …) now updated or completed following the proposed summary in preview section?

Finding:

Is the review fully successful? If not, please indicate what is still missing


Once review is successful, the development must be scheduled for merge during next Merge Party Meeting.