Changeset 10292 for NEMO/branches/2018/dev_r10164_HPC09_ESIWACE_PREP_MERGE/src/ICE/icedyn_adv_umx.F90

Timestamp:

2018-11-09T16:35:08+01:00 (5 years ago)

Author:

smasson

Message:

dev_r10164_HPC09_ESIWACE_PREP_MERGE: action 4b: reduce communications in si3, see #2133

File:

• NEMO/branches/2018/dev_r10164_HPC09_ESIWACE_PREP_MERGE/src/ICE/icedyn_adv_umx.F90 (modified) (4 diffs)

NEMO/branches/2018/dev_r10164_HPC09_ESIWACE_PREP_MERGE/src/ICE/icedyn_adv_umx.F90

@@ -83 +83 @@
       ALLOCATE( zpato(jpi,jpj,1) )
       !
-      ! --- If ice drift field is too fast, use an appropriate time step for advection (CFL test for stability) --- !        
-      zcfl  =            MAXVAL( ABS( pu_ice(:,:) ) * rdt_ice * r1_e1u(:,:) )
-      zcfl  = MAX( zcfl, MAXVAL( ABS( pv_ice(:,:) ) * rdt_ice * r1_e2v(:,:) ) )
-      IF( lk_mpp )   CALL mpp_max( zcfl )
-
-      IF( zcfl > 0.5 ) THEN   ;   initad = 2   ;   zusnit = 0.5_wp
-      ELSE                    ;   initad = 1   ;   zusnit = 1.0_wp
+      ! --- If ice drift field is too fast, use an appropriate time step for advection (CFL test for stability) --- !
+      !     When needed, the advection split is applied at the next time-step in order to avoid blocking global comm.
+      !     ...this should not affect too much the stability... Was ok on the tests we did...
+      zcfl =            MAXVAL( ABS( pu_ice(:,:) ) * rdt_ice * r1_e1u(:,:) )
+      zcfl = MAX( zcfl, MAXVAL( ABS( pv_ice(:,:) ) * rdt_ice * r1_e2v(:,:) ) )
+      IF( zcfl > 0.5 ) THEN   ;   l_split_advumx(1) = .TRUE.    ! split advection time-step if CFL violated
+      ELSE                    ;   l_split_advumx(1) = .FALSE.
+      ENDIF
+      
+      ! non-blocking global communication send l_split_advumx(1) and receive l_split_advumx(2)
+      IF( lk_mpp )   CALL mpp_ilor( l_split_advumx, ldlast = kt == nitend - nn_fsbc + 1 )
+
+      IF( l_split_advumx(2) ) THEN   ;   initad = 2   ;   zusnit = 0.5_wp    ! split defined at the previous time-step
+      ELSE                           ;   initad = 1   ;   zusnit = 1.0_wp
       ENDIF
 
@@ -120 +127 @@
       DO jt = 1, initad
          CALL adv_umx( k_order, kt,   1, zdt, zudy, zvdx, zcu_box, zcv_box, zpato(:,:,1) )        ! Open water area 
+         CALL lbc_lnk( 'icedyn_adv_umx', zpato, 'T',  1. )
          CALL adv_umx( k_order, kt, jpl, zdt, zudy, zvdx, zcu_box, zcv_box, pa_i(:,:,:) )         ! Ice area
          CALL adv_umx( k_order, kt, jpl, zdt, zudy, zvdx, zcu_box, zcv_box, pv_i(:,:,:) )         ! Ice  volume
@@ -127 +135 @@
             CALL adv_umx( k_order, kt, jpl, zdt, zudy, zvdx, zcu_box, zcv_box, pe_i(:,:,jk,:) )   ! Ice  heat content
          END DO
+         CALL lbc_lnk( 'icedyn_adv_umx', pe_i, 'T',  1. )
+
          CALL adv_umx( k_order, kt, jpl, zdt, zudy, zvdx, zcu_box, zcv_box, pv_s(:,:,:) )         ! Snow volume
          DO jk = 1, nlay_s
             CALL adv_umx( k_order, kt, jpl, zdt, zudy, zvdx, zcu_box, zcv_box, pe_s(:,:,jk,:) )   ! Snow heat content
          END DO
+         CALL lbc_lnk( 'icedyn_adv_umx', pe_s, 'T',  1. )
+
          IF ( ln_pnd_H12 ) THEN
             CALL adv_umx( k_order, kt, jpl, zdt, zudy, zvdx, zcu_box, zcv_box, pa_ip(:,:,:) )     ! Melt pond fraction
             CALL adv_umx( k_order, kt, jpl, zdt, zudy, zvdx, zcu_box, zcv_box, pv_ip(:,:,:) )     ! Melt pond volume
+            CALL lbc_lnk_multi( 'icedyn_adv_umx', pa_i, 'T',  1., pv_i, 'T',  1., psv_i, 'T',  1., &
+                                                & poa_i, 'T',  1., pv_s, 'T',  1., pa_ip, 'T',  1., &
+                                                & pv_ip, 'T',  1. )
+         ELSE
+            CALL lbc_lnk_multi( 'icedyn_adv_umx', pa_i, 'T',  1., pv_i, 'T',  1., psv_i, 'T',  1., &
+                                                & poa_i, 'T',  1., pv_s, 'T',  1. )
          ENDIF
       END DO
@@ -249 +267 @@
          END DO
       END DO
-      CALL lbc_lnk( 'icedyn_adv_umx', ptc, 'T',  1. )
       !
    END SUBROUTINE adv_umx