mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-22 04:50:07 +00:00
903bc7dcc2
Both the sysfs and procfs parsing (through GET_NPROCS_PARSER) are removed in favor the syscall. The initial scratch buffer should fit to most of the common usage (1024 bytes with maps to 8192 CPUs). Checked on x86_64-linux-gnu and aarch64-linux-gnu.
42 lines
1.3 KiB
C
42 lines
1.3 KiB
C
/* Copyright (C) 2007-2021 Free Software Foundation, Inc.
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library; if not, see
|
|
<https://www.gnu.org/licenses/>. */
|
|
|
|
#include <sched.h>
|
|
|
|
/* Counting bits set, Brian Kernighan's way.
|
|
Using a open-coded routine is slight better for architectures that
|
|
do not have a popcount instruction (compiler might emit a library
|
|
call). */
|
|
static inline int
|
|
countbits (__cpu_mask v)
|
|
{
|
|
int s = 0;
|
|
for (; v != 0; s++)
|
|
v &= v - 1;
|
|
return s;
|
|
}
|
|
|
|
int
|
|
__sched_cpucount (size_t setsize, const cpu_set_t *setp)
|
|
{
|
|
int s = 0;
|
|
for (int i = 0; i < setsize / sizeof (__cpu_mask); i++)
|
|
s += countbits (setp->__bits[i]);
|
|
return s;
|
|
}
|
|
libc_hidden_def (__sched_cpucount)
|