sched_getcpu - determine CPU on which the calling thread is running

       For an explanation of the terms used in this section, see attributes(7).
       ┌─────────────────────────────────────────────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                                                                   │ Attribute     │ Value   │
       ├─────────────────────────────────────────────────────────────────────────────┼───────────────┼─────────┤
       │ sched_getcpu()                                                              │ Thread safety │ MT-Safe │
       └─────────────────────────────────────────────────────────────────────────────┴───────────────┴─────────┘

sched_getcpu() returns the number of the CPU on which the calling thread is currently executing.

ENOSYS This kernel does not implement getcpu(2).

       glibc 2.6.

       Standard C library (libc, -lc)

       sched_getcpu - determine CPU on which the calling thread is running

       The call

           cpu = sched_getcpu();

       is equivalent to the following getcpu(2) call:

           int c, s;
           s = getcpu(&c, NULL);
           cpu = (s == -1) ? s : c;

       On  success,  sched_getcpu() returns a nonnegative CPU number.  On error, -1 is returned and errno is set
       to indicate the error.

getcpu(2), sched(7)

Linux man-pages 6.9.1                              2024-05-02                                    sched_getcpu(3)

       GNU.

#include<sched.h>intsched_getcpu(void);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       sched_getcpu():
           Since glibc 2.14:
               _GNU_SOURCE
           Before glibc 2.14:
               _BSD_SOURCE || _SVID_SOURCE
                   /* _GNU_SOURCE also suffices */