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/* Copyright (C) 2006-2013 Free Software Foundation, Inc.
Contributed by Jakub Jelinek <jakub@redhat.com>.
This file is part of the GNU OpenMP Library (libgomp).
Libgomp is free software; you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.
Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. See the GNU General Public License for
more details.
Under Section 7 of GPL version 3, you are granted additional
permissions described in the GCC Runtime Library Exception, version
3.1, as published by the Free Software Foundation.
You should have received a copy of the GNU General Public License and
a copy of the GCC Runtime Library Exception along with this program;
see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
<http://www.gnu.org/licenses/>. */
/* This is a Linux specific implementation of a CPU affinity setting. */
#ifndef _GNU_SOURCE
#define _GNU_SOURCE 1
#endif
#include "libgomp.h"
#include "proc.h"
#include <stdlib.h>
#include <unistd.h>
#ifdef HAVE_PTHREAD_AFFINITY_NP
static unsigned int affinity_counter;
void
gomp_init_affinity (void)
{
cpu_set_t cpuset, cpusetnew;
size_t idx, widx;
unsigned long cpus = 0;
if (pthread_getaffinity_np (pthread_self (), sizeof (cpuset), &cpuset))
{
gomp_error ("could not get CPU affinity set");
free (gomp_cpu_affinity);
gomp_cpu_affinity = NULL;
gomp_cpu_affinity_len = 0;
return;
}
CPU_ZERO (&cpusetnew);
if (gomp_cpu_affinity_len == 0)
{
unsigned long count = gomp_cpuset_popcount (&cpuset);
if (count >= 65536)
count = 65536;
gomp_cpu_affinity = malloc (count * sizeof (unsigned short));
if (gomp_cpu_affinity == NULL)
{
gomp_error ("not enough memory to store CPU affinity list");
return;
}
for (widx = idx = 0; widx < count && idx < 65536; idx++)
if (CPU_ISSET (idx, &cpuset))
{
cpus++;
gomp_cpu_affinity[widx++] = idx;
}
}
else
for (widx = idx = 0; idx < gomp_cpu_affinity_len; idx++)
if (gomp_cpu_affinity[idx] < CPU_SETSIZE
&& CPU_ISSET (gomp_cpu_affinity[idx], &cpuset))
{
if (! CPU_ISSET (gomp_cpu_affinity[idx], &cpusetnew))
{
cpus++;
CPU_SET (gomp_cpu_affinity[idx], &cpusetnew);
}
gomp_cpu_affinity[widx++] = gomp_cpu_affinity[idx];
}
if (widx == 0)
{
gomp_error ("no CPUs left for affinity setting");
free (gomp_cpu_affinity);
gomp_cpu_affinity = NULL;
gomp_cpu_affinity_len = 0;
return;
}
gomp_cpu_affinity_len = widx;
if (cpus < gomp_available_cpus)
gomp_available_cpus = cpus;
CPU_ZERO (&cpuset);
CPU_SET (gomp_cpu_affinity[0], &cpuset);
pthread_setaffinity_np (pthread_self (), sizeof (cpuset), &cpuset);
affinity_counter = 1;
}
void
gomp_init_thread_affinity (pthread_attr_t *attr)
{
unsigned int cpu;
cpu_set_t cpuset;
cpu = __atomic_fetch_add (&affinity_counter, 1, MEMMODEL_RELAXED);
cpu %= gomp_cpu_affinity_len;
CPU_ZERO (&cpuset);
CPU_SET (gomp_cpu_affinity[cpu], &cpuset);
pthread_attr_setaffinity_np (attr, sizeof (cpu_set_t), &cpuset);
}
#else
#include "../posix/affinity.c"
#endif
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