diff options
| -rw-r--r-- | tools/testing/selftests/timers/Makefile | 3 | ||||
| -rw-r--r-- | tools/testing/selftests/timers/raw_skew.c | 154 |
2 files changed, 156 insertions, 1 deletions
diff --git a/tools/testing/selftests/timers/Makefile b/tools/testing/selftests/timers/Makefile index dae9ee76b74b..088a791a44cb 100644 --- a/tools/testing/selftests/timers/Makefile +++ b/tools/testing/selftests/timers/Makefile @@ -2,7 +2,7 @@ CC = $(CROSS_COMPILE)gcc BUILD_FLAGS = -DKTEST CFLAGS += -O3 -Wl,-no-as-needed -Wall $(BUILD_FLAGS) LDFLAGS += -lrt -lpthread -bins = posix_timers nanosleep inconsistency-check nsleep-lat +bins = posix_timers nanosleep inconsistency-check nsleep-lat raw_skew all: ${bins} @@ -11,5 +11,6 @@ run_tests: all ./nanosleep ./nsleep-lat ./inconsistency-check + ./raw_skew clean: rm -f ${bins} diff --git a/tools/testing/selftests/timers/raw_skew.c b/tools/testing/selftests/timers/raw_skew.c new file mode 100644 index 000000000000..30906bfd9c1b --- /dev/null +++ b/tools/testing/selftests/timers/raw_skew.c @@ -0,0 +1,154 @@ +/* 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> +#ifdef KTEST +#include "../kselftest.h" +#else +static inline int ksft_exit_pass(void) +{ + exit(0); +} +static inline int ksft_exit_fail(void) +{ + exit(1); +} +#endif + + +#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) { + printf(" [FAILED]\n"); + return ksft_exit_fail(); + } + printf(" [OK]\n"); + return ksft_exit_pass(); +} |