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77 lines
2.5 KiB
Fortran
77 lines
2.5 KiB
Fortran
! @@name: affinity_display.2.f90
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! @@type: F-free
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! @@compilable: yes, omp_5.0
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! @@linkable: yes
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! @@expect: success
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program affinity_display
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use omp_lib
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implicit none
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character(len=0) :: null
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integer :: n_sockets, socket_num, n_thrds_on_socket;
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call omp_set_nested(.true.) ! or env var= OMP_NESTED=true
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call omp_set_max_active_levels(2) ! or env var= OMP_MAX_ACTIVE_LEVELS=2
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n_sockets = omp_get_num_places()
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n_thrds_on_socket = omp_get_place_num_procs(0)
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! OMP_NUM_THREADS=2,4
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! OMP_PLACES="{0,2,4,6},{1,3,5,7}" #2 sockets; even/odd proc-ids
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! OMP_AFFINITY_FORMAT=\
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! "nest_level= %L, parent_thrd_num= %a, thrd_num= %n, thrd_affinity= %A"
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!$omp parallel num_threads(n_sockets) private(socket_num)
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socket_num = omp_get_place_num()
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if(socket_num==0) then
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write(*,'("LEVEL 1 AFFINITIES 1 thread/socket ",i0," sockets")')n_sockets
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endif
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call omp_display_affinity(null) !not needed if OMP_DISPLAY_AFFINITY=TRUE
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! OUTPUT:
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! LEVEL 1 AFFINITIES 1 thread/socket, 2 sockets:
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! nest_level= 1, parent_thrd_num= 0, thrd_num= 0, thrd_affinity= 0,2,4,6
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! nest_level= 1, parent_thrd_num= 0, thrd_num= 1, thrd_affinity= 1,3,5,7
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call socket_work(socket_num, n_thrds_on_socket)
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!$omp end parallel
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end program
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subroutine socket_work(socket_num, n_thrds)
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implicit none
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integer :: socket_num, n_thrds
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character(len=0) :: null
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!$omp parallel num_threads(n_thrds)
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if(omp_get_thread_num()==0) then
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write(*,'("LEVEL 2 AFFINITIES, ",i0," threads on socket ",i0)') &
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n_thrds,socket_num
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endif
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call omp_display_affinity(null); !not needed if OMP_DISPLAY_AFFINITY=TRUE
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! OUTPUT:
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! LEVEL 2 AFFINITIES, 4 threads on socket 0
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! nest_level= 2, parent_thrd_num= 0, thrd_num= 0, thrd_affinity= 0
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! nest_level= 2, parent_thrd_num= 0, thrd_num= 1, thrd_affinity= 2
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! nest_level= 2, parent_thrd_num= 0, thrd_num= 2, thrd_affinity= 4
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! nest_level= 2, parent_thrd_num= 0, thrd_num= 3, thrd_affinity= 6
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! LEVEL 2 AFFINITIES, 4 thrds on socket 1
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! nest_level= 2, parent_thrd_num= 1, thrd_num= 0, thrd_affinity= 1
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! nest_level= 2, parent_thrd_num= 1, thrd_num= 1, thrd_affinity= 3
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! nest_level= 2, parent_thrd_num= 1, thrd_num= 2, thrd_affinity= 5
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! nest_level= 2, parent_thrd_num= 1, thrd_num= 3, thrd_affinity= 7
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! ... Do Some work on Socket
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!$omp end parallel
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end subroutine
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