mirror of
https://sourceware.org/git/glibc.git
synced 2024-12-05 11:11:04 +00:00
56 lines
1.8 KiB
C
56 lines
1.8 KiB
C
/* Determine whether the host has multiple processors. Linux version.
|
|
Copyright (C) 1996-2017 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 Library General Public License as
|
|
published by the Free Software Foundation; either version 2 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
|
|
Library General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public
|
|
License along with the GNU C Library; see the file COPYING.LIB. If
|
|
not, see <http://www.gnu.org/licenses/>. */
|
|
|
|
#include <errno.h>
|
|
#include <fcntl.h>
|
|
#include <string.h>
|
|
#include <sys/utsname.h>
|
|
#include <not-cancel.h>
|
|
|
|
/* Test whether the machine has more than one processor. This is not the
|
|
best test but good enough. More complicated tests would require `malloc'
|
|
which is not available at that time. */
|
|
static inline int
|
|
is_smp_system (void)
|
|
{
|
|
union
|
|
{
|
|
struct utsname uts;
|
|
char buf[512];
|
|
} u;
|
|
char *cp;
|
|
|
|
/* Try reading the number using `sysctl' first. */
|
|
if (uname (&u.uts) == 0)
|
|
cp = u.uts.version;
|
|
else
|
|
{
|
|
/* This was not successful. Now try reading the /proc filesystem. */
|
|
int fd = open_not_cancel_2 ("/proc/sys/kernel/version", O_RDONLY);
|
|
if (__builtin_expect (fd, 0) == -1
|
|
|| read_not_cancel (fd, u.buf, sizeof (u.buf)) <= 0)
|
|
/* This also didn't work. We give up and say it's a UP machine. */
|
|
u.buf[0] = '\0';
|
|
|
|
close_not_cancel_no_status (fd);
|
|
cp = u.buf;
|
|
}
|
|
|
|
return strstr (cp, "SMP") != NULL;
|
|
}
|