PROGRAM find_palm_config !------------------------------------------------------------------------------! ! Description: ! ------------- ! Find possible configurations for given processor and grid point numbers !------------------------------------------------------------------------------! IMPLICIT NONE CHARACTER (LEN=1) :: char = '' INTEGER :: count = 0, i, ii(1), j, k, maximum_grid_level, mg_levels_x, & mg_levels_y, mg_levels_z, n, numprocs, numprocs_max, & numprocs_min, nx, nxanz, nx_max, nx_min, ny, nyanz, ny_max, & ny_min, nz, nz_max, nz_min, pdims(2) INTEGER :: numnx(10000), numpr(10000) LOGICAL :: cubic_domain = .FALSE., found, found_once = .FALSE., & one_d_decomp = .FALSE., quadratic_domain_xy = .FALSE. REAL :: grid_ratio, grid_ratio_new, maximum_grid_ratio, tolerance, & tolerance_nx, tolerance_ny, tolerance_nz REAL :: gridratio(10000) TYPE configuration REAL :: grid_ratio INTEGER :: numprocs, pdims_1, pdims_2, nx, ny, nz, nxanz, & nyanz, grid_levels, nx_mg, ny_mg, nz_mg END TYPE configuration TYPE(configuration), DIMENSION(10000) :: config ! !-- Ask number of processors available PRINT*, '*** number of PEs available + allowed tolerance:' READ (*,*) numprocs, tolerance IF ( tolerance < 0.0 ) THEN numprocs_max = numprocs numprocs_min = numprocs * ( 1.0 + tolerance ) ELSE numprocs_max = numprocs * ( 1.0 + tolerance ) numprocs_min = numprocs * ( 1.0 - tolerance ) ENDIF ! !-- Ask for 1D-decomposition PRINT*, ' ' PRINT*, ' ' PRINT*, '*** shall a 1d-decomposition along x be used (y/n)?' READ (*,*) char IF ( char == 'y' ) one_d_decomp = .TRUE. ! !-- Ask for quadratic domain PRINT*, ' ' PRINT*, ' ' PRINT*, '*** shall a quadratic domain along x and y be used (y/n)?' READ (*,*) char IF ( char == 'y' ) THEN quadratic_domain_xy = .TRUE. PRINT*, ' ' PRINT*, ' ' PRINT*, '*** shall also grid points along z be equal to x and y (y/n)?' READ (*,*) char IF ( char == 'y' ) cubic_domain = .TRUE. ENDIF ! !-- Read number of gridpoints in each direction PRINT*, ' ' PRINT*, ' ' PRINT*, '*** please type nx + allowed tolerance:' READ (*,*) nx, tolerance_nx IF ( tolerance_nx < 0.0 ) THEN nx_max = nx nx_min = nx * ( 1.0 + tolerance_nx ) ELSE nx_max = nx * ( 1.0 + tolerance_nx ) nx_min = nx * ( 1.0 - tolerance_nx ) ENDIF IF ( quadratic_domain_xy ) THEN ny = nx tolerance_ny = tolerance_nx ELSE PRINT*, '*** please type ny + allowed tolerance:' READ (*,*) ny, tolerance_ny ENDIF IF ( tolerance_ny < 0.0 ) THEN ny_max = ny ny_min = ny * ( 1.0 + tolerance_ny ) ELSE ny_max = ny * ( 1.0 + tolerance_ny ) ny_min = ny * ( 1.0 - tolerance_ny ) ENDIF IF ( cubic_domain ) THEN nz = nx tolerance_nz = tolerance_nx ELSE PRINT*, '*** please type nz + allowed tolerance:' READ (*,*) nz, tolerance_nz ENDIF IF ( tolerance_nz < 0.0 ) THEN nz_max = nz nz_min = nz * ( 1.0 + tolerance_nz ) ELSE nz_max = nz * ( 1.0 + tolerance_nz ) nz_min = nz * ( 1.0 - tolerance_nz ) ENDIF ! !-- Read maximum gridpoint-ratio for which results shall be printed PRINT*, ' ' PRINT*, '*** please type maximum subdomain gridpoint-ratio' PRINT*, ' ( ABS( nx_sub / ny_sub - 1.0 ) ) for which results shall be' PRINT*, ' printed' READ (*,*) maximum_grid_ratio ! !-- Loop over allowed numbers of processors g: DO n = numprocs_max, numprocs_min, -1 ! !-- Set initial configuration numprocs = n pdims(1) = numprocs + 1 pdims(2) = 1 ! !-- Looking for practicable virtual processor grids p: DO WHILE ( pdims(1) > 1 ) pdims(1) = pdims(1) - 1 ! !-- Create the virtual PE-grid topology IF ( MOD( numprocs , pdims(1) ) /= 0 ) THEN CYCLE p ELSE IF ( one_d_decomp .AND. pdims(1) < numprocs ) CYCLE g ENDIF pdims(2) = numprocs / pdims(1) xn: DO nx = nx_min, nx_max ! !-- Proof, if grid points in x-direction can be distributed without !-- rest to the processors in x- and y-direction IF ( MOD(nx+1, pdims(1)) /= 0 .OR. & MOD(nx+1, pdims(2)) /= 0 ) CYCLE xn nxanz = ( nx + 1 ) / pdims(1) yn: DO ny = ny_min, ny_max ! !-- Eventually exit in case of non quadratic domains IF ( quadratic_domain_xy .AND. ny /= nx ) CYCLE yn ! !-- Proof, if grid points in y-direction can be distributed without !-- rest to the processors in x- and y-direction IF ( MOD( ny+1 , pdims(2) ) /= 0 .OR. & MOD( ny+1, pdims(1) ) /= 0 ) CYCLE yn nyanz = ( ny + 1 ) / pdims(2) grid_ratio = ABS( REAL( nxanz ) / REAL( nyanz ) - 1.0 ) zn: DO nz = nz_min, nz_max ! !-- Eventually exit in case of non cubic domains IF ( cubic_domain .AND. nz /= nx ) CYCLE zn ! !-- Proof, if grid points in z-direction can be distributed !-- without rest to the processors in x-direction IF ( MOD( nz, pdims(1) ) /= 0 .AND. .NOT. one_d_decomp ) & THEN CYCLE zn ENDIF ! !-- Store configuration found IF ( grid_ratio < maximum_grid_ratio ) THEN found = .TRUE. count = count + 1 config(count)%grid_ratio = grid_ratio config(count)%numprocs = numprocs config(count)%pdims_1 = pdims(1) config(count)%pdims_2 = pdims(2) config(count)%nx = nx config(count)%ny = ny config(count)%nz = nz config(count)%nxanz = nxanz config(count)%nyanz = nyanz IF ( count == 10000 ) THEN PRINT*, '+++ more than 10000 configurations' EXIT g ENDIF ENDIF IF ( one_d_decomp ) CYCLE yn ENDDO zn ENDDO yn ENDDO xn ENDDO p ENDDO g IF ( .NOT. found ) THEN PRINT*, ' ' PRINT*, '+++ No valid processor grid found for the given number of' PRINT*, ' processors and gridpoints' STOP ENDIF ! !-- Calculate number of possible grid levels and gridpoints of the coarsest grid !-- used by the multigrid method DO n = 1, count mg_levels_x = 1 mg_levels_y = 1 mg_levels_z = 1 i = config(n)%nxanz DO WHILE ( MOD( i, 2 ) == 0 .AND. i /= 2 ) i = i / 2 mg_levels_x = mg_levels_x + 1 ENDDO j = config(n)%nyanz DO WHILE ( MOD( j, 2 ) == 0 .AND. j /= 2 ) j = j / 2 mg_levels_y = mg_levels_y + 1 ENDDO k = config(n)%nz DO WHILE ( MOD( k, 2 ) == 0 .AND. k /= 2 ) k = k / 2 mg_levels_z = mg_levels_z + 1 ENDDO maximum_grid_level = MIN( mg_levels_x, mg_levels_y, mg_levels_z ) config(n)%grid_levels = maximum_grid_level config(n)%nx_mg = config(n)%nxanz / 2**(maximum_grid_level-1) config(n)%ny_mg = config(n)%nyanz / 2**(maximum_grid_level-1) config(n)%nz_mg = config(n)%nz / 2**(maximum_grid_level-1) ENDDO ! !-- Print the configurations computed above PRINT*, ' ' PRINT*, ' ' PRINT*, '*** print out results in ascending grid-ratio order (y/n)?' READ (*,*) char IF ( char == 'y' ) THEN gridratio = 10000.0 gridratio(1:count) = config(1:count)%grid_ratio WRITE ( *, * ) ' ' WRITE ( *, * ) 'Possible configurations found:' WRITE ( *, * ) 'sorted in ascending grid-ratio order' WRITE ( *, 100 ) DO ii = MINLOC( gridratio ) i = ii(1) IF ( gridratio(i) /= 10000.0 ) THEN WRITE ( *, 101 ) & config(i)%grid_ratio, config(i)%numprocs, config(i)%pdims_1, & config(i)%pdims_2, config(i)%nx, config(i)%ny, config(i)%nz, & config(i)%nxanz, config(i)%nyanz, config(i)%grid_levels, & config(i)%nx_mg, config(i)%ny_mg, config(i)%nz_mg gridratio(i) = 10000.0 ELSE EXIT ENDIF ENDDO ENDIF PRINT*, ' ' PRINT*, ' ' PRINT*, '*** print out results in descending PE order (y/n)?' READ (*,*) char IF ( char == 'y' ) THEN numpr = 0 numpr(1:count) = config(1:count)%numprocs WRITE ( *, * ) ' ' WRITE ( *, * ) 'Possible configurations found:' WRITE ( *, * ) 'sorted after number of PEs' WRITE ( *, 100 ) DO ii = MAXLOC( numpr ) i = ii(1) IF ( numpr(i) /= 0 ) THEN WRITE ( *, 101 ) & config(i)%grid_ratio, config(i)%numprocs, config(i)%pdims_1, & config(i)%pdims_2, config(i)%nx, config(i)%ny, config(i)%nz, & config(i)%nxanz, config(i)%nyanz, config(i)%grid_levels, & config(i)%nx_mg, config(i)%ny_mg, config(i)%nz_mg numpr(i) = 0 ELSE EXIT ENDIF ENDDO ENDIF PRINT*, ' ' PRINT*, ' ' PRINT*, '*** print out results in descending grid size order (y/n)?' READ (*,*) char IF ( char == 'y' ) THEN numnx = 0 DO i = 1, count numnx(i) = config(i)%nx * config(i)%ny * config(i)%nz ENDDO WRITE ( *, * ) ' ' WRITE ( *, * ) 'Possible configurations found:' WRITE ( *, * ) 'sorted after grid size' WRITE ( *, 100 ) DO ii = MAXLOC( numnx ) i = ii(1) IF ( numnx(i) /= 0 ) THEN WRITE ( *, 101 ) & config(i)%grid_ratio, config(i)%numprocs, config(i)%pdims_1, & config(i)%pdims_2, config(i)%nx, config(i)%ny, config(i)%nz, & config(i)%nxanz, config(i)%nyanz, config(i)%grid_levels, & config(i)%nx_mg, config(i)%ny_mg, config(i)%nz_mg numnx(i) = 0 ELSE EXIT ENDIF ENDDO ENDIF 100 FORMAT('ratio PEs PE-grid nx ny nz subdomain grid_levels ', & 'coarsest subd.') 101 FORMAT(F4.2,2X,I4,' (',I4,',',I4,')',2X,I4,1X,I4,1X,I4,' (',I4,',',I4,')', & 5X,I2,7X,'(',I3,',',I3,',',I3,')') END PROGRAM find_palm_config