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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 values in /proc/uptime increment monotonically
// while shifting across CPUs.
#define _GNU_SOURCE
#undef NDEBUG
#include <assert.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)
{
unsigned int len;
unsigned long *m;
unsigned int cpu;
uint64_t u0, u1, i0, i1;
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) == -EINVAL);
fd = open("/proc/uptime", O_RDONLY);
assert(fd >= 0);
proc_uptime(fd, &u0, &i0);
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);
proc_uptime(fd, &u1, &i1);
assert(u1 >= u0);
assert(i1 >= i0);
u0 = u1;
i0 = i1;
}
return 0;
}
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