mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-25 05:17:28 +07:00
1416270f4a
In the past we've warned when ADJ_OFFSET was in progress, usually caused by ntpd or some other time adjusting daemon running in non steady sate, which can cause the skew calculations to be incorrect. Thus, this patch checks to see if the clock was being adjusted when we fail so that we don't cause false negatives. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Miroslav Lichvar <mlichvar@redhat.com> Cc: Richard Cochran <richardcochran@gmail.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Stephen Boyd <sboyd@kernel.org> Cc: Shuah Khan <shuah@kernel.org> Cc: linux-kselftest@vger.kernel.org Suggested-by: Miroslav Lichvar <mlichvar@redhat.com> Signed-off-by: John Stultz <john.stultz@linaro.org> --- v2: Widened the checks to look for other clock adjustments that could happen, as suggested by Miroslav v3: Fixed up commit message
148 lines
3.6 KiB
C
148 lines
3.6 KiB
C
/* CLOCK_MONOTONIC vs CLOCK_MONOTONIC_RAW skew test
|
|
* by: john stultz (johnstul@us.ibm.com)
|
|
* John Stultz <john.stultz@linaro.org>
|
|
* (C) Copyright IBM 2012
|
|
* (C) Copyright Linaro Limited 2015
|
|
* Licensed under the GPLv2
|
|
*
|
|
* To build:
|
|
* $ gcc raw_skew.c -o raw_skew -lrt
|
|
*
|
|
* This program is free software: you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation, either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <unistd.h>
|
|
#include <stdlib.h>
|
|
#include <sys/time.h>
|
|
#include <sys/timex.h>
|
|
#include <time.h>
|
|
#include "../kselftest.h"
|
|
|
|
#define CLOCK_MONOTONIC_RAW 4
|
|
#define NSEC_PER_SEC 1000000000LL
|
|
|
|
#define shift_right(x, s) ({ \
|
|
__typeof__(x) __x = (x); \
|
|
__typeof__(s) __s = (s); \
|
|
__x < 0 ? -(-__x >> __s) : __x >> __s; \
|
|
})
|
|
|
|
long long llabs(long long val)
|
|
{
|
|
if (val < 0)
|
|
val = -val;
|
|
return val;
|
|
}
|
|
|
|
unsigned long long ts_to_nsec(struct timespec ts)
|
|
{
|
|
return ts.tv_sec * NSEC_PER_SEC + ts.tv_nsec;
|
|
}
|
|
|
|
struct timespec nsec_to_ts(long long ns)
|
|
{
|
|
struct timespec ts;
|
|
|
|
ts.tv_sec = ns/NSEC_PER_SEC;
|
|
ts.tv_nsec = ns%NSEC_PER_SEC;
|
|
return ts;
|
|
}
|
|
|
|
long long diff_timespec(struct timespec start, struct timespec end)
|
|
{
|
|
long long start_ns, end_ns;
|
|
|
|
start_ns = ts_to_nsec(start);
|
|
end_ns = ts_to_nsec(end);
|
|
return end_ns - start_ns;
|
|
}
|
|
|
|
void get_monotonic_and_raw(struct timespec *mon, struct timespec *raw)
|
|
{
|
|
struct timespec start, mid, end;
|
|
long long diff = 0, tmp;
|
|
int i;
|
|
|
|
for (i = 0; i < 3; i++) {
|
|
long long newdiff;
|
|
|
|
clock_gettime(CLOCK_MONOTONIC, &start);
|
|
clock_gettime(CLOCK_MONOTONIC_RAW, &mid);
|
|
clock_gettime(CLOCK_MONOTONIC, &end);
|
|
|
|
newdiff = diff_timespec(start, end);
|
|
if (diff == 0 || newdiff < diff) {
|
|
diff = newdiff;
|
|
*raw = mid;
|
|
tmp = (ts_to_nsec(start) + ts_to_nsec(end))/2;
|
|
*mon = nsec_to_ts(tmp);
|
|
}
|
|
}
|
|
}
|
|
|
|
int main(int argv, char **argc)
|
|
{
|
|
struct timespec mon, raw, start, end;
|
|
long long delta1, delta2, interval, eppm, ppm;
|
|
struct timex tx1, tx2;
|
|
|
|
setbuf(stdout, NULL);
|
|
|
|
if (clock_gettime(CLOCK_MONOTONIC_RAW, &raw)) {
|
|
printf("ERR: NO CLOCK_MONOTONIC_RAW\n");
|
|
return -1;
|
|
}
|
|
|
|
tx1.modes = 0;
|
|
adjtimex(&tx1);
|
|
get_monotonic_and_raw(&mon, &raw);
|
|
start = mon;
|
|
delta1 = diff_timespec(mon, raw);
|
|
|
|
if (tx1.offset)
|
|
printf("WARNING: ADJ_OFFSET in progress, this will cause inaccurate results\n");
|
|
|
|
printf("Estimating clock drift: ");
|
|
sleep(120);
|
|
|
|
get_monotonic_and_raw(&mon, &raw);
|
|
end = mon;
|
|
tx2.modes = 0;
|
|
adjtimex(&tx2);
|
|
delta2 = diff_timespec(mon, raw);
|
|
|
|
interval = diff_timespec(start, end);
|
|
|
|
/* calculate measured ppm between MONOTONIC and MONOTONIC_RAW */
|
|
eppm = ((delta2-delta1)*NSEC_PER_SEC)/interval;
|
|
eppm = -eppm;
|
|
printf("%lld.%i(est)", eppm/1000, abs((int)(eppm%1000)));
|
|
|
|
/* Avg the two actual freq samples adjtimex gave us */
|
|
ppm = (tx1.freq + tx2.freq) * 1000 / 2;
|
|
ppm = (long long)tx1.freq * 1000;
|
|
ppm = shift_right(ppm, 16);
|
|
printf(" %lld.%i(act)", ppm/1000, abs((int)(ppm%1000)));
|
|
|
|
if (llabs(eppm - ppm) > 1000) {
|
|
if (tx1.offset || tx2.offset ||
|
|
tx1.freq != tx2.freq || tx1.tick != tx2.tick) {
|
|
printf(" [SKIP]\n");
|
|
return ksft_exit_skip("The clock was adjusted externally. Shutdown NTPd or other time sync daemons\n");
|
|
}
|
|
printf(" [FAILED]\n");
|
|
return ksft_exit_fail();
|
|
}
|
|
printf(" [OK]\n");
|
|
return ksft_exit_pass();
|
|
}
|