1 /*
2 * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15 */
16 // Test that values in /proc/uptime increment monotonically
17 // while shifting across CPUs.
18 #define _GNU_SOURCE
19 #undef NDEBUG
20 #include <assert.h>
21 #include <unistd.h>
22 #include <sys/syscall.h>
23 #include <stdlib.h>
24 #include <string.h>
25
26 #include <stdint.h>
27 #include <sys/types.h>
28 #include <sys/stat.h>
29 #include <fcntl.h>
30
31 #include "proc-uptime.h"
32
sys_sched_getaffinity(pid_t pid,unsigned int len,unsigned long * m)33 static inline int sys_sched_getaffinity(pid_t pid, unsigned int len, unsigned long *m)
34 {
35 return syscall(SYS_sched_getaffinity, pid, len, m);
36 }
37
sys_sched_setaffinity(pid_t pid,unsigned int len,unsigned long * m)38 static inline int sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned long *m)
39 {
40 return syscall(SYS_sched_setaffinity, pid, len, m);
41 }
42
main(void)43 int main(void)
44 {
45 unsigned int len;
46 unsigned long *m;
47 unsigned int cpu;
48 uint64_t u0, u1, i0, i1;
49 int fd;
50
51 /* find out "nr_cpu_ids" */
52 m = NULL;
53 len = 0;
54 do {
55 len += sizeof(unsigned long);
56 free(m);
57 m = malloc(len);
58 } while (sys_sched_getaffinity(0, len, m) == -EINVAL);
59
60 fd = open("/proc/uptime", O_RDONLY);
61 assert(fd >= 0);
62
63 proc_uptime(fd, &u0, &i0);
64 for (cpu = 0; cpu < len * 8; cpu++) {
65 memset(m, 0, len);
66 m[cpu / (8 * sizeof(unsigned long))] |= 1UL << (cpu % (8 * sizeof(unsigned long)));
67
68 /* CPU might not exist, ignore error */
69 sys_sched_setaffinity(0, len, m);
70
71 proc_uptime(fd, &u1, &i1);
72 assert(u1 >= u0);
73 assert(i1 >= i0);
74 u0 = u1;
75 i0 = i1;
76 }
77
78 return 0;
79 }
80
