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1/*2 * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>3 *4 * Permission to use, copy, modify, and distribute this software for any5 * purpose with or without fee is hereby granted, provided that the above6 * copyright notice and this permission notice appear in all copies.7 *8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.15 */16// Test that boottime value in /proc/uptime and CLOCK_BOOTTIME increment17// monotonically while shifting across CPUs. We don't test idle time18// monotonicity due to broken iowait task counting, cf: comment above19// get_cpu_idle_time_us()20#undef NDEBUG21#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 35static 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 40static 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 45int 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