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Ticket Diff – NEMO

Changes between Version 8 and Version 9 of Ticket #1943


Ignore:
Timestamp:
2018-12-20T10:24:14+01:00 (5 years ago)
Author:
francesca
Comment:

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  • Ticket #1943

    • Property Status changed from assigned to closed
    • Property Resolution changed from to fixed
    • Property Wp_comment changed from The improvement of the hybrid fine-grained and coarse-grained approaches is under discussion within the NEMO HPC-WG. The action will be completed and the ticket will be closed by the end of 2018. No development branch to be included in NEMO 4.0 to Hybrid fine-grained and coarse-grained approaches have been tested and results have been discussed within the HPC-WG (see Conclusion section). No development branch to be included in NEMO 4.0.

  • Ticket #1943 – Description

    v8 v9  
    12127. extension of the approach to the tracers advection (2018)  --> done 
    13138. definition of the computational performance test plan and performance evaluation on CMCC HPC system (2018)  --> done 
    14 9. discussion with the HPC-WG (2018)  --> ongoing 
     149. discussion with the HPC-WG (2018)  --> done 
     15 
     16== Conclusions == 
     17 
     18The introduction of the OpenMP directives, following the fine grained or course grained approach, heavily impacts on code maintainability. The effort required from the ocean models developers to maintain the NEMO code with the OpenMP support is not rewarded by the improvement of the code performance. The development of the second level of parallelisation based on shared memory will be reconsidered when new code refactoring more suitable for OpenMP will be found. In this regards, the tiling approach that will be investigated in 2019 in the context of the IMMERSE project could reduce the impact of OpenMP directives, making the hybrid code maintainability more easy.