1*4882a593Smuzhiyun /*
2*4882a593Smuzhiyun * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
3*4882a593Smuzhiyun *
4*4882a593Smuzhiyun * Permission to use, copy, modify, and distribute this software for any
5*4882a593Smuzhiyun * purpose with or without fee is hereby granted, provided that the above
6*4882a593Smuzhiyun * copyright notice and this permission notice appear in all copies.
7*4882a593Smuzhiyun *
8*4882a593Smuzhiyun * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9*4882a593Smuzhiyun * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10*4882a593Smuzhiyun * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
11*4882a593Smuzhiyun * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12*4882a593Smuzhiyun * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
13*4882a593Smuzhiyun * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
14*4882a593Smuzhiyun * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15*4882a593Smuzhiyun */
16*4882a593Smuzhiyun // Test that values in /proc/uptime increment monotonically
17*4882a593Smuzhiyun // while shifting across CPUs.
18*4882a593Smuzhiyun #undef NDEBUG
19*4882a593Smuzhiyun #include <assert.h>
20*4882a593Smuzhiyun #include <unistd.h>
21*4882a593Smuzhiyun #include <sys/syscall.h>
22*4882a593Smuzhiyun #include <stdlib.h>
23*4882a593Smuzhiyun #include <string.h>
24*4882a593Smuzhiyun
25*4882a593Smuzhiyun #include <stdint.h>
26*4882a593Smuzhiyun #include <sys/types.h>
27*4882a593Smuzhiyun #include <sys/stat.h>
28*4882a593Smuzhiyun #include <fcntl.h>
29*4882a593Smuzhiyun
30*4882a593Smuzhiyun #include "proc-uptime.h"
31*4882a593Smuzhiyun
sys_sched_getaffinity(pid_t pid,unsigned int len,unsigned long * m)32*4882a593Smuzhiyun static inline int sys_sched_getaffinity(pid_t pid, unsigned int len, unsigned long *m)
33*4882a593Smuzhiyun {
34*4882a593Smuzhiyun return syscall(SYS_sched_getaffinity, pid, len, m);
35*4882a593Smuzhiyun }
36*4882a593Smuzhiyun
sys_sched_setaffinity(pid_t pid,unsigned int len,unsigned long * m)37*4882a593Smuzhiyun static inline int sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned long *m)
38*4882a593Smuzhiyun {
39*4882a593Smuzhiyun return syscall(SYS_sched_setaffinity, pid, len, m);
40*4882a593Smuzhiyun }
41*4882a593Smuzhiyun
main(void)42*4882a593Smuzhiyun int main(void)
43*4882a593Smuzhiyun {
44*4882a593Smuzhiyun unsigned int len;
45*4882a593Smuzhiyun unsigned long *m;
46*4882a593Smuzhiyun unsigned int cpu;
47*4882a593Smuzhiyun uint64_t u0, u1, i0, i1;
48*4882a593Smuzhiyun int fd;
49*4882a593Smuzhiyun
50*4882a593Smuzhiyun /* find out "nr_cpu_ids" */
51*4882a593Smuzhiyun m = NULL;
52*4882a593Smuzhiyun len = 0;
53*4882a593Smuzhiyun do {
54*4882a593Smuzhiyun len += sizeof(unsigned long);
55*4882a593Smuzhiyun free(m);
56*4882a593Smuzhiyun m = malloc(len);
57*4882a593Smuzhiyun } while (sys_sched_getaffinity(0, len, m) == -EINVAL);
58*4882a593Smuzhiyun
59*4882a593Smuzhiyun fd = open("/proc/uptime", O_RDONLY);
60*4882a593Smuzhiyun assert(fd >= 0);
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun proc_uptime(fd, &u0, &i0);
63*4882a593Smuzhiyun for (cpu = 0; cpu < len * 8; cpu++) {
64*4882a593Smuzhiyun memset(m, 0, len);
65*4882a593Smuzhiyun m[cpu / (8 * sizeof(unsigned long))] |= 1UL << (cpu % (8 * sizeof(unsigned long)));
66*4882a593Smuzhiyun
67*4882a593Smuzhiyun /* CPU might not exist, ignore error */
68*4882a593Smuzhiyun sys_sched_setaffinity(0, len, m);
69*4882a593Smuzhiyun
70*4882a593Smuzhiyun proc_uptime(fd, &u1, &i1);
71*4882a593Smuzhiyun assert(u1 >= u0);
72*4882a593Smuzhiyun assert(i1 >= i0);
73*4882a593Smuzhiyun u0 = u1;
74*4882a593Smuzhiyun i0 = i1;
75*4882a593Smuzhiyun }
76*4882a593Smuzhiyun
77*4882a593Smuzhiyun return 0;
78*4882a593Smuzhiyun }
79