cegcc/src/gcc-4.3.2/libgomp/config/linux/affinity.c

   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
  40 static unsigned int affinity_counter;
  41 #ifndef HAVE_SYNC_BUILTINS
  42 static gomp_mutex_t affinity_lock;
  43 #endif
  44
  45 void
  46 gomp_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
  84 void
  85 gomp_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