Re: [PATCH v18 5/7] kexec: exclude hot remove cpu from elfcorehdr notes

[Thomas Gleixner]

On Mon, Feb 13 2023 at 10:10, Sourabh Jain wrote:
> The sysconf document says _SC_NPROCESSORS_CONF is processors configured, 
> isn't that equivalent to possible CPUs?

glibc tries to evaluate that in the following order:

  1) /sys/devices/system/cpu/cpu*

     That's present CPUs not possible CPUs

  2) /proc/stat

     That's online CPUs

  3) sched_getaffinity()

     That's online CPUs at best. In the worst case it's an affinity mask
     which is set on a process group

Thanks,

        tglx