1/* Copyright (C) 2006, 2007 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 Lesser General Public License as published by 8 the Free Software Foundation; either version 2.1 of the License, or 9 (at your option) 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 Lesser General Public License for 14 more details. 15 16 You should have received a copy of the GNU Lesser General Public License 17 along with libgomp; see the file COPYING.LIB. If not, write to the 18 Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 19 MA 02110-1301, USA. */ 20 21/* As a special exception, if you link this library with other files, some 22 of which are compiled with GCC, to produce an executable, this library 23 does not by itself cause the resulting executable to be covered by the 24 GNU General Public License. This exception does not however invalidate 25 any other reasons why the executable file might be covered by the GNU 26 General Public License. */ 27 28/* This is a Linux specific implementation of a CPU affinity setting. */ 29 30#ifndef _GNU_SOURCE 31#define _GNU_SOURCE 1 32#endif 33#include "libgomp.h" 34#include <sched.h> 35#include <stdlib.h> 36#include <unistd.h> 37 38#ifdef HAVE_PTHREAD_AFFINITY_NP 39 40static unsigned int affinity_counter; 41#ifndef HAVE_SYNC_BUILTINS 42static gomp_mutex_t affinity_lock; 43#endif 44 45void 46gomp_init_affinity (void) 47{ 48 cpu_set_t cpuset; 49 size_t idx, widx; 50 51 if (pthread_getaffinity_np (pthread_self (), sizeof (cpuset), &cpuset)) 52 { 53 gomp_error ("could not get CPU affinity set"); 54 free (gomp_cpu_affinity); 55 gomp_cpu_affinity = NULL; 56 gomp_cpu_affinity_len = 0; 57 return; 58 } 59 60 for (widx = idx = 0; idx < gomp_cpu_affinity_len; idx++) 61 if (gomp_cpu_affinity[idx] < CPU_SETSIZE 62 && CPU_ISSET (gomp_cpu_affinity[idx], &cpuset)) 63 gomp_cpu_affinity[widx++] = gomp_cpu_affinity[idx]; 64 65 if (widx == 0) 66 { 67 gomp_error ("no CPUs left for affinity setting"); 68 free (gomp_cpu_affinity); 69 gomp_cpu_affinity = NULL; 70 gomp_cpu_affinity_len = 0; 71 return; 72 } 73 74 gomp_cpu_affinity_len = widx; 75 CPU_ZERO (&cpuset); 76 CPU_SET (gomp_cpu_affinity[0], &cpuset); 77 pthread_setaffinity_np (pthread_self (), sizeof (cpuset), &cpuset); 78 affinity_counter = 1; 79#ifndef HAVE_SYNC_BUILTINS 80 gomp_mutex_init (&affinity_lock); 81#endif 82} 83 84void 85gomp_init_thread_affinity (pthread_attr_t *attr) 86{ 87 unsigned int cpu; 88 cpu_set_t cpuset; 89 90#ifdef HAVE_SYNC_BUILTINS 91 cpu = __sync_fetch_and_add (&affinity_counter, 1); 92#else 93 gomp_mutex_lock (&affinity_lock); 94 cpu = affinity_counter++; 95 gomp_mutex_unlock (&affinity_lock); 96#endif 97 cpu %= gomp_cpu_affinity_len; 98 CPU_ZERO (&cpuset); 99 CPU_SET (gomp_cpu_affinity[cpu], &cpuset); 100 pthread_attr_setaffinity_np (attr, sizeof (cpu_set_t), &cpuset); 101} 102 103#else 104 105#include "../posix/affinity.c" 106 107#endif 108