Re: lib/58679: sched_getaffinity_np() always returns an empty set

["Christos Zoulas via gnats" <gnats-admin%NetBSD.org@localhost>]

The following reply was made to PR lib/58679; it has been noted by GNATS.

From: Christos Zoulas <christos%zoulas.com@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: lib-bug-people%netbsd.org@localhost, gnats-admin%netbsd.org@localhost,
 netbsd-bugs%netbsd.org@localhost, ondrej%sury.org@localhost
Subject: Re: lib/58679: sched_getaffinity_np() always returns an empty set
Date: Thu, 19 Sep 2024 10:14:26 -0400

 Not really a bug.
 
 christos
 
 [10:10am] 26>cat getaffinity.c
 #include <sched.h>
 #include <unistd.h>
 #include <err.h>
 #include <stdio.h>
 
 static int
 cpu_count(cpuset_t *cpuset)
 {
          int             rc;
          cpuid_t         i;
 
          rc = 0;
          for (i = 0;; i++) {
                  int             r = cpuset_isset(i, cpuset);
                  fprintf(stderr, "cpuset_isset(%d, %p) -> %d\n", (int)i, 
 cpuset, r);
                  if (r < 0)
                          break;
                  if (r)
                          rc++;
          }
 
          return rc;
 }
 
 
 int
 main(void)
 {
          int             rc = -1;
          cpuset_t       *set = cpuset_create();
          if (set != NULL) {
                  cpuset_set(0, set);
                  if (-1 == sched_setaffinity_np(getpid(), 
 cpuset_size(set), set))
                          err(1, "setaffinity");
                  if (0 == sched_getaffinity_np(getpid(), 
 cpuset_size(set), set))
                          rc = cpu_count(set);
                  cpuset_destroy(set);
          }
 
          printf("Number of processors reported by sched_getaffinity_np: 
 %d\n", rc);
 
          if (rc < 1)
                  rc = sysconf(_SC_NPROCESSORS_ONLN);
 
          printf("Number of processors reported by 
 sysconf(_SC_NPROCESSORS_ONLN): %d\n", rc);
 
          return 0;
 }