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/*
* Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
// Test that boottime value in /proc/uptime and CLOCK_BOOTTIME increment
// monotonically while shifting across CPUs. We don't test idle time
// monotonicity due to broken iowait task counting, cf: comment above
// get_cpu_idle_time_us()
#undef NDEBUG
#include <assert.h>
#include <errno.h>
#include <unistd.h>
#include <sys/syscall.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "proc-uptime.h"
static inline int sys_sched_getaffinity(pid_t pid, unsigned int len, unsigned long *m)
{
return syscall(SYS_sched_getaffinity, pid, len, m);
}
static inline int sys_sched_setaffinity(pid_t pid, unsigned int len, unsigned long *m)
{
return syscall(SYS_sched_setaffinity, pid, len, m);
}
int main(void)
{
uint64_t u0, u1, c0, c1;
unsigned int len;
unsigned long *m;
unsigned int cpu;
int fd;
/* find out "nr_cpu_ids" */
m = NULL;
len = 0;
do {
len += sizeof(unsigned long);
free(m);
m = malloc(len);
} while (sys_sched_getaffinity(0, len, m) == -1 && errno == EINVAL);
fd = open("/proc/uptime", O_RDONLY);
assert(fd >= 0);
u0 = proc_uptime(fd);
c0 = clock_boottime();
for (cpu = 0; cpu < len * 8; cpu++) {
memset(m, 0, len);
m[cpu / (8 * sizeof(unsigned long))] |= 1UL << (cpu % (8 * sizeof(unsigned long)));
/* CPU might not exist, ignore error */
sys_sched_setaffinity(0, len, m);
u1 = proc_uptime(fd);
c1 = clock_boottime();
/* Is /proc/uptime monotonic ? */
assert(u1 >= u0);
/* Is CLOCK_BOOTTIME monotonic ? */
assert(c1 >= c0);
/* Is CLOCK_BOOTTIME VS /proc/uptime monotonic ? */
assert(c0 >= u0);
u0 = u1;
c0 = c1;
}
return 0;
}
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