/*
|
*
|
* Copyright (c) Novell Inc. 2011
|
*
|
* This program is free software; you can redistribute it and/or modify
|
* it under the terms in version 2 of the GNU General Public License as
|
* published by the Free Software Foundation.
|
*
|
* This program 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.
|
*
|
* You should have received a copy of the GNU General Public License
|
* along with this program; if not, write to the Free Software
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
*
|
* Author: Peter W. Morreale <pmorreale AT novell DOT com>
|
* Date: 11/08/2011
|
*/
|
|
/*
|
* Must be ported to OS's other than Linux
|
*/
|
|
#ifdef __linux__
|
# define _GNU_SOURCE
|
# define AFFINITY_NEEDS_GNU_SOURCE 1
|
# include <sched.h>
|
# include <stdio.h>
|
|
static int set_affinity(int cpu)
|
{
|
cpu_set_t mask;
|
|
CPU_ZERO(&mask);
|
CPU_SET(cpu, &mask);
|
|
return (sched_setaffinity(0, sizeof(cpu_set_t), &mask));
|
}
|
|
static int get_online_cpu_from_sysfs(void)
|
{
|
FILE *f;
|
int cpu = -1;
|
|
f = fopen("/sys/devices/system/cpu/online", "r");
|
if (!f)
|
return -1;
|
fscanf(f, "%d", &cpu);
|
fclose(f);
|
|
return cpu;
|
}
|
|
static int get_online_cpu_from_cpuinfo(void)
|
{
|
FILE *f;
|
int cpu = -1;
|
char line[4096];
|
|
f = fopen("/proc/cpuinfo", "r");
|
if (!f)
|
return -1;
|
|
while (!feof(f)) {
|
if (!fgets(line, sizeof(line), f))
|
return -1;
|
/*
|
* cpuinfo output is not consistent across all archictures,
|
* it can be "processor : N", but for example on s390
|
* it's: "processor N: ...", so ignore any non-number
|
* after "processor"
|
*/
|
if (sscanf(line, "processor%*[^0123456789]%d", &cpu) == 1)
|
break;
|
}
|
fclose(f);
|
|
return cpu;
|
}
|
|
static int set_affinity_single(void)
|
{
|
int cpu;
|
|
cpu = get_online_cpu_from_sysfs();
|
if (cpu >= 0)
|
goto set_affinity;
|
|
cpu = get_online_cpu_from_cpuinfo();
|
if (cpu >= 0)
|
goto set_affinity;
|
|
fprintf(stderr, "WARNING: Failed to detect online cpu, using cpu=0\n");
|
cpu = 0;
|
set_affinity:
|
return set_affinity(cpu);
|
}
|
|
#else
|
#include <errno.h>
|
|
static int set_affinity_single(void)
|
{
|
errno = ENOSYS;
|
return -1;
|
}
|
#endif
|
