New URL for NEMO forge!   http://forge.nemo-ocean.eu

Since March 2022 along with NEMO 4.2 release, the code development moved to a self-hosted GitLab.
This present forge is now archived and remained online for history.
ticket/0871 – NEMO
wiki:ticket/0871

Version 3 (modified by edblockley, 12 years ago) (diff)

--

Last edited Timestamp?


Author : Ed Blockley

ticket : #871

Branch : dev_r2802_UKMET3_rebuild


Description


Testing

Testing could consider (where appropriate) other configurations in addition to NVTK].

NVTK Tested'''N/A'''
Other model configurations'''YES'''
Processor configurations tested[ 4*8, 8*4, 5*6, 8*12, 8*16 ]
If adding new functionality please confirm that the
New code doesn't change results when it is switched off
and ''works'' when switched on
'''N/A'''

(Answering UNSURE is likely to generate further questions from reviewers.)

'Please add further summary details here'

  • The rebuild code is a stand-alone code and does not impact on any existing NEMO configurations
  • It has however been tested by rebuilding files on many different processor configurations as detailed in the table above
  • The OMP parallelisation has been tested by running with many different numbers of threads - all of which bit compare
  • The code has been tested with many different types of file including vn3.2 restart files, vn3.2 diagnostics, vn3.3.1 diagnostics

Bit Comparability

Does this change preserve answers in your tested standard configurations (to the last bit) ?'''YES '''
Does this change bit compare across various processor configurations. (1xM, Nx1 and MxN are recommended)'''YES'''
Is this change expected to preserve answers in all possible model configurations?'''YES'''
Is this change expected to preserve all diagnostics?
,,''Preserving answers in model runs does not necessarily imply preserved diagnostics. ''
'''YES'''

If you answered '''NO''' to any of the above, please provide further details:

  • Which routine(s) are causing the difference?
  • Why the changes are not protected by a logical switch or new section-version
  • What is needed to achieve regression with the previous model release (e.g. a regression branch, hand-edits etc). If this is not possible, explain why not.
  • What do you expect to see occur in the test harness jobs?
  • Which diagnostics have you altered and why have they changed?Please add details here........

System Changes

Does your change alter namelists?'''NO '''
Does your change require a change in compiler options?'''YES'''

If any of these apply, please document the changes required here.......

  • The rebuild uses its own namelist (nam_rebuild) but this is very simple and can be constructed on the fly by the rebuild_nemo script
  • In order to use OMP optimisations compile options will need to be changed - for this I shall create _omp specific compile configs in https://forge.ipsl.jussieu.fr/nemo/browser/trunk/NEMOGCM/ARCH/

Resources

''Please ''summarize'' any changes in runtime or memory use caused by this change......''

This rebuild is considerably faster than the IOIPSL rebuild but does use a little more memory. However the memory requirements can be reduced by using the 'time-chunking' functionality which splits 4D variables up into chunks over the record (4th) dimension.


IPR issues

Has the code been wholly (100%) produced by NEMO developers staff working exclusively on NEMO?'''YES'''

If No:

  • Identify the collaboration agreement details
  • Ensure the code routine header is in accordance with the agreement, (Copyright/Redistribution? etc).Add further details here if required..........