Commit 1f5bd054 authored by Alexey Dobriyan's avatar Alexey Dobriyan Committed by Linus Torvalds

proc: selftests: test /proc/uptime

The only tests I could come up with for /proc/uptime are:
 - test that values increase monotonically for 1 second,
 - bounce around CPUs and test the same thing.

Avoid glibc like plague for affinity given patches like this:
https://marc.info/?l=linux-kernel&m=152130031912594&w=4

Link: http://lkml.kernel.org/r/20180317165235.GB3445@avx2Signed-off-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4f113437
......@@ -3,4 +3,6 @@
/proc-self-map-files-002
/proc-self-syscall
/proc-self-wchan
/proc-uptime-001
/proc-uptime-002
/read
......@@ -6,6 +6,8 @@ TEST_GEN_PROGS += proc-self-map-files-001
TEST_GEN_PROGS += proc-self-map-files-002
TEST_GEN_PROGS += proc-self-syscall
TEST_GEN_PROGS += proc-self-wchan
TEST_GEN_PROGS += proc-uptime-001
TEST_GEN_PROGS += proc-uptime-002
TEST_GEN_PROGS += read
include ../lib.mk
/*
* 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.
#undef NDEBUG
#include <assert.h>
#include <stdint.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "proc-uptime.h"
int main(void)
{
uint64_t start, u0, u1, i0, i1;
int fd;
fd = open("/proc/uptime", O_RDONLY);
assert(fd >= 0);
proc_uptime(fd, &u0, &i0);
start = u0;
do {
proc_uptime(fd, &u1, &i1);
assert(u1 >= u0);
assert(i1 >= i0);
u0 = u1;
i0 = i1;
} while (u1 - start < 100);
return 0;
}
/*
* 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;
}
/*
* 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.
*/
#undef NDEBUG
#include <assert.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
static unsigned long long xstrtoull(const char *p, char **end)
{
if (*p == '0') {
*end = (char *)p + 1;
return 0;
} else if ('1' <= *p && *p <= '9') {
unsigned long long val;
errno = 0;
val = strtoull(p, end, 10);
assert(errno == 0);
return val;
} else
assert(0);
}
static void proc_uptime(int fd, uint64_t *uptime, uint64_t *idle)
{
uint64_t val1, val2;
char buf[64], *p;
ssize_t rv;
/* save "p < end" checks */
memset(buf, 0, sizeof(buf));
rv = pread(fd, buf, sizeof(buf), 0);
assert(0 <= rv && rv <= sizeof(buf));
buf[sizeof(buf) - 1] = '\0';
p = buf;
val1 = xstrtoull(p, &p);
assert(p[0] == '.');
assert('0' <= p[1] && p[1] <= '9');
assert('0' <= p[2] && p[2] <= '9');
assert(p[3] == ' ');
val2 = (p[1] - '0') * 10 + p[2] - '0';
*uptime = val1 * 100 + val2;
p += 4;
val1 = xstrtoull(p, &p);
assert(p[0] == '.');
assert('0' <= p[1] && p[1] <= '9');
assert('0' <= p[2] && p[2] <= '9');
assert(p[3] == '\n');
val2 = (p[1] - '0') * 10 + p[2] - '0';
*idle = val1 * 100 + val2;
assert(p + 4 == buf + rv);
}
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