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 boottime value in /proc/uptime and CLOCK_BOOTTIME increment |
17 | // monotonically while shifting across CPUs. We don't test idle time |
18 | // monotonicity due to broken iowait task counting, cf: comment above |
19 | // get_cpu_idle_time_us() |
20 | #undef NDEBUG |
21 | #include <assert.h> |
22 | #include <errno.h> |
23 | #include <unistd.h> |
24 | #include <sys/syscall.h> |
25 | #include <stdlib.h> |
26 | #include <string.h> |
27 | |
28 | #include <stdint.h> |
29 | #include <sys/types.h> |
30 | #include <sys/stat.h> |
31 | #include <fcntl.h> |
32 | |
33 | #include "proc-uptime.h" |
34 | |
35 | static inline int sys_sched_getaffinity(pid_t pid, unsigned int len, unsigned long *m) |
36 | { |
37 | return syscall(SYS_sched_getaffinity, pid, len, m); |
38 | } |
39 | |
40 | static inline int sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned long *m) |
41 | { |
42 | return syscall(SYS_sched_setaffinity, pid, len, m); |
43 | } |
44 | |
45 | int main(void) |
46 | { |
47 | uint64_t u0, u1, c0, c1; |
48 | unsigned int len; |
49 | unsigned long *m; |
50 | unsigned int cpu; |
51 | int fd; |
52 | |
53 | /* find out "nr_cpu_ids" */ |
54 | m = NULL; |
55 | len = 0; |
56 | do { |
57 | len += sizeof(unsigned long); |
58 | free(m); |
59 | m = malloc(len); |
60 | } while (sys_sched_getaffinity(0, len, m) == -1 && errno == EINVAL); |
61 | |
62 | fd = open("/proc/uptime" , O_RDONLY); |
63 | assert(fd >= 0); |
64 | |
65 | u0 = proc_uptime(fd); |
66 | c0 = clock_boottime(); |
67 | |
68 | for (cpu = 0; cpu < len * 8; cpu++) { |
69 | memset(m, 0, len); |
70 | m[cpu / (8 * sizeof(unsigned long))] |= 1UL << (cpu % (8 * sizeof(unsigned long))); |
71 | |
72 | /* CPU might not exist, ignore error */ |
73 | sys_sched_setaffinity(0, len, m); |
74 | |
75 | u1 = proc_uptime(fd); |
76 | c1 = clock_boottime(); |
77 | |
78 | /* Is /proc/uptime monotonic ? */ |
79 | assert(u1 >= u0); |
80 | |
81 | /* Is CLOCK_BOOTTIME monotonic ? */ |
82 | assert(c1 >= c0); |
83 | |
84 | /* Is CLOCK_BOOTTIME VS /proc/uptime monotonic ? */ |
85 | assert(c0 >= u0); |
86 | |
87 | u0 = u1; |
88 | c0 = c1; |
89 | } |
90 | |
91 | return 0; |
92 | } |
93 | |