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7bb1b2c9 | 1 | /* Determine whether the host has multiple processors. Linux version. |
04277e02 | 2 | Copyright (C) 1996-2019 Free Software Foundation, Inc. |
7bb1b2c9 UD |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Library General Public License as | |
7 | published by the Free Software Foundation; either version 2 of the | |
8 | License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Library General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Library General Public | |
59ba27a6 | 16 | License along with the GNU C Library; see the file COPYING.LIB. If |
5a82c748 | 17 | not, see <https://www.gnu.org/licenses/>. */ |
7bb1b2c9 UD |
18 | |
19 | #include <errno.h> | |
20 | #include <fcntl.h> | |
21 | #include <string.h> | |
22 | #include <sys/utsname.h> | |
23 | #include <not-cancel.h> | |
24 | ||
25 | /* Test whether the machine has more than one processor. This is not the | |
26 | best test but good enough. More complicated tests would require `malloc' | |
27 | which is not available at that time. */ | |
28 | static inline int | |
29 | is_smp_system (void) | |
30 | { | |
31 | union | |
32 | { | |
fbbc73b3 | 33 | struct utsname uts; |
7bb1b2c9 | 34 | char buf[512]; |
fbbc73b3 | 35 | } u; |
7bb1b2c9 UD |
36 | char *cp; |
37 | ||
38 | /* Try reading the number using `sysctl' first. */ | |
fa872e1b | 39 | if (__uname (&u.uts) == 0) |
fbbc73b3 | 40 | cp = u.uts.version; |
7bb1b2c9 UD |
41 | else |
42 | { | |
43 | /* This was not successful. Now try reading the /proc filesystem. */ | |
329ea513 | 44 | int fd = __open64_nocancel ("/proc/sys/kernel/version", O_RDONLY); |
7bb1b2c9 | 45 | if (__builtin_expect (fd, 0) == -1 |
a748eb31 | 46 | || __read_nocancel (fd, u.buf, sizeof (u.buf)) <= 0) |
7bb1b2c9 | 47 | /* This also didn't work. We give up and say it's a UP machine. */ |
fbbc73b3 | 48 | u.buf[0] = '\0'; |
7bb1b2c9 | 49 | |
c181840c | 50 | __close_nocancel_nostatus (fd); |
fbbc73b3 | 51 | cp = u.buf; |
7bb1b2c9 UD |
52 | } |
53 | ||
54 | return strstr (cp, "SMP") != NULL; | |
55 | } |