http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58642
--- Comment #7 from vincenzo Innocente <vincenzo.innocente at cern dot ch> ---
getconf -a | grep _NPROCESSORS
_NPROCESSORS_CONF 32
_NPROCESSORS_ONLN 32
ls -l /sys/devices/system/cpu/
total 0
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu0
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu1
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu10
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu11
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu12
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu13
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu14
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu15
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu16
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu17
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu18
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu19
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu2
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu20
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu21
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu22
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu23
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu24
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu25
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu26
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu27
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu28
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu29
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu3
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu30
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu31
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu4
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu5
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu6
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu7
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu8
drwxr-xr-x 8 root root 0 Sep 2 17:44 cpu9
drwxr-xr-x 2 root root 0 Sep 2 17:45 cpufreq
drwxr-xr-x 2 root root 0 Sep 2 17:45 cpuidle
drwxr-xr-x 2 root root 0 Oct 7 08:43 intel_pstate
-r--r--r-- 1 root root 4096 Oct 7 08:43 kernel_max
-r--r--r-- 1 root root 4096 Oct 7 08:43 modalias
-r--r--r-- 1 root root 4096 Oct 7 08:43 offline
-r--r--r-- 1 root root 4096 Sep 2 18:06 online
-r--r--r-- 1 root root 4096 Oct 7 08:43 possible
drwxr-xr-x 2 root root 0 Oct 7 08:43 power
-r--r--r-- 1 root root 4096 Oct 7 08:43 present
--w------- 1 root root 4096 Oct 7 08:43 probe
--w------- 1 root root 4096 Oct 7 08:43 release
-rw-r--r-- 1 root root 4096 Oct 7 08:43 uevent
dmesg | grep 'Allowing.*CPUs'
smpboot: Allowing 128 CPUs, 96 hotplug CPUs
#include <sched.h>
#include <stdio.h>
#include <errno.h>
int main(void)
{
cpu_set_t k[32];
sched_getaffinity(0, 8, k);
sched_getaffinity(0, 10, k);
sched_getaffinity(0, 12, k);
sched_getaffinity(0, 16, k);
strace ./a.out |& grep affin
sched_getaffinity(0, 8, 0x7fffbcf19420) = -1 EINVAL (Invalid argument)
sched_getaffinity(0, 10, 0x7fffbcf19420) = -1 EINVAL (Invalid argument)
sched_getaffinity(0, 12, 0x7fffbcf19420) = -1 EINVAL (Invalid argument)
sched_getaffinity(0, 16, { ffffffff, 0 }) = 16
