mirror of
https://github.com/OpenMP/Examples.git
synced 2025-04-04 05:41:33 +01:00
79 lines
2.3 KiB
C
79 lines
2.3 KiB
C
/*
|
|
* @@name: affinity_display.2
|
|
* @@type: C
|
|
* @@compilable: yes
|
|
* @@linkable: yes
|
|
* @@expect: success
|
|
* @@version: omp_5.0
|
|
*/
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <omp.h>
|
|
|
|
void socket_work(int socket_num, int n_thrds);
|
|
|
|
int main(void)
|
|
{
|
|
int n_sockets, socket_num, n_thrds_on_socket;
|
|
|
|
omp_set_nested(1); // or env var= OMP_NESTED=true
|
|
omp_set_max_active_levels(2); // or env var= OMP_MAX_ACTIVE_LEVELS=2
|
|
|
|
n_sockets = omp_get_num_places();
|
|
n_thrds_on_socket = omp_get_place_num_procs(0);
|
|
|
|
// OMP_NUM_THREADS=2,4
|
|
// OMP_PLACES="{0,2,4,6},{1,3,5,7}" #2 sockets; even/odd proc-ids
|
|
// OMP_AFFINITY_FORMAT=\
|
|
// "nest_level= %L, parent_thrd_num= %a, thrd_num= %n, thrd_affinity= %A"
|
|
|
|
#pragma omp parallel num_threads(n_sockets) private(socket_num)
|
|
{
|
|
socket_num = omp_get_place_num();
|
|
|
|
if(socket_num==0)
|
|
printf(" LEVEL 1 AFFINITIES 1 thread/socket, %d sockets:\n\n",
|
|
n_sockets);
|
|
|
|
// not needed if OMP_DISPLAY_AFFINITY=TRUE
|
|
omp_display_affinity(NULL);
|
|
|
|
// OUTPUT:
|
|
// LEVEL 1 AFFINITIES 1 thread/socket, 2 sockets:
|
|
// nest_level= 1, parent_thrd_num= 0, thrd_num= 0, thrd_affinity= 0,2,4,6
|
|
// nest_level= 1, parent_thrd_num= 0, thrd_num= 1, thrd_affinity= 1,3,5,7
|
|
|
|
socket_work(socket_num, n_thrds_on_socket);
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
void socket_work(int socket_num, int n_thrds)
|
|
{
|
|
#pragma omp parallel num_threads(n_thrds)
|
|
{
|
|
if(omp_get_thread_num()==0)
|
|
printf(" LEVEL 2 AFFINITIES, %d threads on socket %d\n",
|
|
n_thrds, socket_num);
|
|
|
|
// not needed if OMP_DISPLAY_AFFINITY=TRUE
|
|
omp_display_affinity(NULL);
|
|
|
|
// OUTPUT:
|
|
// LEVEL 2 AFFINITIES, 4 threads on socket 0
|
|
// nest_level= 2, parent_thrd_num= 0, thrd_num= 0, thrd_affinity= 0
|
|
// nest_level= 2, parent_thrd_num= 0, thrd_num= 1, thrd_affinity= 2
|
|
// nest_level= 2, parent_thrd_num= 0, thrd_num= 2, thrd_affinity= 4
|
|
// nest_level= 2, parent_thrd_num= 0, thrd_num= 3, thrd_affinity= 6
|
|
|
|
// LEVEL 2 AFFINITIES, 4 threads on socket 1
|
|
// nest_level= 2, parent_thrd_num= 1, thrd_num= 0, thrd_affinity= 1
|
|
// nest_level= 2, parent_thrd_num= 1, thrd_num= 1, thrd_affinity= 3
|
|
// nest_level= 2, parent_thrd_num= 1, thrd_num= 2, thrd_affinity= 5
|
|
// nest_level= 2, parent_thrd_num= 1, thrd_num= 3, thrd_affinity= 7
|
|
|
|
// ... Do Some work on Socket
|
|
}
|
|
}
|