mirror of https://github.com/Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
148 lines
3.6 KiB
148 lines
3.6 KiB
/* CLOCK_MONOTONIC vs CLOCK_MONOTONIC_RAW skew test |
|
* by: john stultz ([email protected]) |
|
* John Stultz <[email protected]> |
|
* (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: "); |
|
fflush(stdout); |
|
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(); |
|
}
|
|
|