1/* Copyright (C) 2007-2023 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18#include <sched.h>
19
20/* Counting bits set, Brian Kernighan's way.
21 Using a open-coded routine is slight better for architectures that
22 do not have a popcount instruction (compiler might emit a library
23 call). */
24static inline int
25countbits (__cpu_mask v)
26{
27 int s = 0;
28 for (; v != 0; s++)
29 v &= v - 1;
30 return s;
31}
32
33int
34__sched_cpucount (size_t setsize, const cpu_set_t *setp)
35{
36 int s = 0;
37 for (int i = 0; i < setsize / sizeof (__cpu_mask); i++)
38 s += countbits (setp->__bits[i]);
39 return s;
40}
41libc_hidden_def (__sched_cpucount)
42