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/*
* Copyright (c) 2012 Fujitsu Ltd.
* Author: Wanlong Gao <gaowanlong@cn.fujitsu.com>
*
* This program 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 2 of the License, or
* (at your option) any later version.
*
* 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
*/
#include <stdlib.h>
#include <unistd.h>
#include "test.h"
#include "safe_macros.h"
long tst_ncpus(void)
{
long ncpus = -1;
#ifdef _SC_NPROCESSORS_ONLN
ncpus = SAFE_SYSCONF(NULL, _SC_NPROCESSORS_ONLN);
#else
tst_brkm(TBROK, NULL, "could not determine number of CPUs online");
#endif
return ncpus;
}
long tst_ncpus_conf(void)
{
long ncpus_conf = -1;
#ifdef _SC_NPROCESSORS_CONF
ncpus_conf = SAFE_SYSCONF(NULL, _SC_NPROCESSORS_CONF);
#else
tst_brkm(TBROK, NULL, "could not determine number of CPUs configured");
#endif
return ncpus_conf;
}
#define KERNEL_MAX "/sys/devices/system/cpu/kernel_max"
long tst_ncpus_max(void)
{
long ncpus_max = -1;
struct stat buf;
/* sched_getaffinity() and sched_setaffinity() cares about number of
* possible CPUs the OS or hardware can support, which can be larger
* than what sysconf(_SC_NPROCESSORS_CONF) currently provides
* (by enumarating /sys/devices/system/cpu/cpu* entries).
*
* Use /sys/devices/system/cpu/kernel_max, if available. This
* represents NR_CPUS-1, a compile time option which specifies
* "maximum number of CPUs which this kernel will support".
* This should provide cpu mask size large enough for any purposes. */
if (stat(KERNEL_MAX, &buf) == 0) {
SAFE_FILE_SCANF(NULL, KERNEL_MAX, "%ld", &ncpus_max);
/* this is maximum CPU index allowed by the kernel
* configuration, so # of cpus allowed by config is +1 */
ncpus_max++;
} else {
/* fall back to _SC_NPROCESSORS_CONF */
ncpus_max = tst_ncpus_conf();
}
return ncpus_max;
}
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