1 /* Copyright (C) 2006-2013 Free Software Foundation, Inc. 2 Contributed by Jakub Jelinek <jakub@redhat.com>. 3 4 This file is part of the GNU OpenMP Library (libgomp). 5 6 Libgomp is free software; you can redistribute it and/or modify it 7 under the terms of the GNU General Public License as published by 8 the Free Software Foundation; either version 3, or (at your option) 9 any later version. 10 11 Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY 12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS 13 FOR A PARTICULAR PURPOSE. See the GNU General Public License for 14 more details. 15 16 Under Section 7 of GPL version 3, you are granted additional 17 permissions described in the GCC Runtime Library Exception, version 18 3.1, as published by the Free Software Foundation. 19 20 You should have received a copy of the GNU General Public License and 21 a copy of the GCC Runtime Library Exception along with this program; 22 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 23 <http://www.gnu.org/licenses/>. */ 24 25 /* This is a Linux specific implementation of a CPU affinity setting. */ 26 27 #ifndef _GNU_SOURCE 28 #define _GNU_SOURCE 1 29 #endif 30 #include "libgomp.h" 31 #include "proc.h" 32 #include <stdlib.h> 33 #include <unistd.h> 34 35 #ifdef HAVE_PTHREAD_AFFINITY_NP 36 37 static unsigned int affinity_counter; 38 39 void 40 gomp_init_affinity (void) 41 { 42 cpu_set_t cpuset, cpusetnew; 43 size_t idx, widx; 44 unsigned long cpus = 0; 45 46 if (pthread_getaffinity_np (pthread_self (), sizeof (cpuset), &cpuset)) 47 { 48 gomp_error ("could not get CPU affinity set"); 49 free (gomp_cpu_affinity); 50 gomp_cpu_affinity = NULL; 51 gomp_cpu_affinity_len = 0; 52 return; 53 } 54 55 CPU_ZERO (&cpusetnew); 56 if (gomp_cpu_affinity_len == 0) 57 { 58 unsigned long count = gomp_cpuset_popcount (&cpuset); 59 if (count >= 65536) 60 count = 65536; 61 gomp_cpu_affinity = malloc (count * sizeof (unsigned short)); 62 if (gomp_cpu_affinity == NULL) 63 { 64 gomp_error ("not enough memory to store CPU affinity list"); 65 return; 66 } 67 for (widx = idx = 0; widx < count && idx < 65536; idx++) 68 if (CPU_ISSET (idx, &cpuset)) 69 { 70 cpus++; 71 gomp_cpu_affinity[widx++] = idx; 72 } 73 } 74 else 75 for (widx = idx = 0; idx < gomp_cpu_affinity_len; idx++) 76 if (gomp_cpu_affinity[idx] < CPU_SETSIZE 77 && CPU_ISSET (gomp_cpu_affinity[idx], &cpuset)) 78 { 79 if (! CPU_ISSET (gomp_cpu_affinity[idx], &cpusetnew)) 80 { 81 cpus++; 82 CPU_SET (gomp_cpu_affinity[idx], &cpusetnew); 83 } 84 gomp_cpu_affinity[widx++] = gomp_cpu_affinity[idx]; 85 } 86 87 if (widx == 0) 88 { 89 gomp_error ("no CPUs left for affinity setting"); 90 free (gomp_cpu_affinity); 91 gomp_cpu_affinity = NULL; 92 gomp_cpu_affinity_len = 0; 93 return; 94 } 95 96 gomp_cpu_affinity_len = widx; 97 if (cpus < gomp_available_cpus) 98 gomp_available_cpus = cpus; 99 CPU_ZERO (&cpuset); 100 CPU_SET (gomp_cpu_affinity[0], &cpuset); 101 pthread_setaffinity_np (pthread_self (), sizeof (cpuset), &cpuset); 102 affinity_counter = 1; 103 } 104 105 void 106 gomp_init_thread_affinity (pthread_attr_t *attr) 107 { 108 unsigned int cpu; 109 cpu_set_t cpuset; 110 111 cpu = __atomic_fetch_add (&affinity_counter, 1, MEMMODEL_RELAXED); 112 cpu %= gomp_cpu_affinity_len; 113 CPU_ZERO (&cpuset); 114 CPU_SET (gomp_cpu_affinity[cpu], &cpuset); 115 pthread_attr_setaffinity_np (attr, sizeof (cpu_set_t), &cpuset); 116 } 117 118 #else 119 120 #include "../posix/affinity.c" 121 122 #endif 123