Mateusz Guzik <mjgu...@gmail.com> writes:
> On 2/14/23, Jan Beich <jbe...@freebsd.org> wrote:
>
>> Steffen Nurpmeso <stef...@sdaoden.eu> writes:
>>
>>> |+ if (all_flag) {
>>> |+ cpus = sysconf(_SC_NPROCESSORS_ONLN);
>>>
>>> is not compatible -- note i like the FreeBSD way better, and maybe
>>> someone should make a bug report even.
>>>
>>> #?0|kent:$ getconf -a|grep NPROC
>>> _NPROCESSORS_CONF 8
>>> _NPROCESSORS_ONLN 4
>>
>> See also https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=230330
>>
>> $ cpuset -l 2-5 -- getconf -a | fgrep _NPROC
>> _NPROCESSORS_CONF: 8
>> _NPROCESSORS_ONLN: 4
>>
>
> As I mentioned previously in the thread, on linux these *don't* react
> to cpusets (or tasksets in linux parlance):
>
> $ getconf -a | grep _NPROC
> _NPROCESSORS_CONF 4
> _NPROCESSORS_ONLN 4
> $ taskset --cpu-list 0 getconf -a | grep _NPROC
> _NPROCESSORS_CONF 4
> _NPROCESSORS_ONLN 4
>
> consequently the patch proposed in the bz would introduce an
> incompatibility with linux
I've used kern.smp.cpus in old patches but found musl more practical.
_SC_NPROCESSORS_ONLN is often used as a default number of jobs.
glibc:
- /sys/devices/system/cpu/online
- /proc/stat
- sched_getaffinity
musl:
- sched_getaffinity
bionic:
- /sys/devices/system/cpu/online
- /proc/stat (Android < 7)
