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Ticket Diff – NEMO

Changes between Initial Version and Version 6 of Ticket #2010


Ignore:
Timestamp:
2018-10-11T18:55:37+02:00 (5 years ago)
Author:
francesca
Comment:

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  • Ticket #2010

    • Property Status changed from new to assigned
    • Property Owner changed from mocavero to francesca
    • Property Wp_comment changed from to The analysis on global communications has been updated on the trunk and the development branch has been created. A list of communications that can be safely removed is reported in the "Implementation plan" section. They will be removed in the development branch and the ticket will be closed by the end of this year.
    • Property Milestone changed from 2018 WP to 2018 release-4.0
  • Ticket #2010 – Description

    initial v6  
    11== Context 
    22 
    3 Reducing MPI communications overhead 
     3Reducing MPI communications overhead by conditioning or removing some global communications 
    44 
    55== Implementation plan 
    66 
    7 Starting from the analysis and classification done in 2017, it will be validated on the new trunk and discussed with the ST in order to reduce the number of global communications. 
     71. two glob_sum can be conditioned during the freshwater budget control (sbc_fwb routine)  
     82. a glob_sum is executed at each time step during the computation of the carbon flux (p4z_flx routine) even if it is used only at output and restart writing time. It can be conditioned. 
     93. three glob_sum are used to compute the loss of biogenic silicon (p4z_sed routine). One of them can be removed because the result is not used 
     104. four glob_sum are used during the correction to the artificial negative concentrations (trc_rad_sms routine). Two of them can be conditioned depending on the result of the other ones 
     115. a global communication (mpp_max) is used for the convergence test in the ice_dyn_rhg_evp routine. It can be removed because the result is not used 
     126. a global communication (mpp_max) is used to stop the control loop on the flux delimiters (wetting/drying routines). The control frequency could be reduced