From 7a5de5512296fd2ab7a497e4a576196b1f046e78 Mon Sep 17 00:00:00 2001 From: Miroslav Lichvar Date: Tue, 13 Jun 2017 12:57:07 +0200 Subject: kselftests: timers: Fix inconsistency-check to not ignore first timestamp When the first timestamp in the list of clock readings was later than the second timestamp and all other timestamps were in order, the inconsistency was not reported because the index of the out-of-order timestamp was equal to the default value. Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Miroslav Lichvar Cc: Richard Cochran Cc: Prarit Bhargava Cc: Stephen Boyd Cc: Shuah Khan Signed-off-by: Miroslav Lichvar Signed-off-by: John Stultz --- tools/testing/selftests/timers/inconsistency-check.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'tools') diff --git a/tools/testing/selftests/timers/inconsistency-check.c b/tools/testing/selftests/timers/inconsistency-check.c index caf1bc9257c4..74c60e8759a0 100644 --- a/tools/testing/selftests/timers/inconsistency-check.c +++ b/tools/testing/selftests/timers/inconsistency-check.c @@ -118,7 +118,7 @@ int consistency_test(int clock_type, unsigned long seconds) start_str = ctime(&t); while (seconds == -1 || now - then < seconds) { - inconsistent = 0; + inconsistent = -1; /* Fill list */ for (i = 0; i < CALLS_PER_LOOP; i++) @@ -130,7 +130,7 @@ int consistency_test(int clock_type, unsigned long seconds) inconsistent = i; /* display inconsistency */ - if (inconsistent) { + if (inconsistent >= 0) { unsigned long long delta; printf("\%s\n", start_str); -- cgit From 767392565a3e618950fe1a5ff1ba11295f6332f4 Mon Sep 17 00:00:00 2001 From: Miroslav Lichvar Date: Fri, 9 Jun 2017 13:43:17 +0200 Subject: kselftests: timers: Add test for frequency step This test checks the response of the system clock to frequency steps made with adjtimex(). The frequency error and stability of the CLOCK_MONOTONIC clock relative to the CLOCK_MONOTONIC_RAW clock is measured in two intervals following the step. The test fails if values from the second interval exceed specified limits. Cc: Thomas Gleixner Cc: Ingo Molnar Cc: Miroslav Lichvar Cc: Richard Cochran Cc: Prarit Bhargava Cc: Stephen Boyd Cc: Shuah Khan Signed-off-by: Miroslav Lichvar Signed-off-by: John Stultz --- tools/testing/selftests/timers/Makefile | 5 +- tools/testing/selftests/timers/freq-step.c | 268 +++++++++++++++++++++++++++++ 2 files changed, 271 insertions(+), 2 deletions(-) create mode 100644 tools/testing/selftests/timers/freq-step.c (limited to 'tools') diff --git a/tools/testing/selftests/timers/Makefile b/tools/testing/selftests/timers/Makefile index 5fa1d7e9a915..5801bbefbe89 100644 --- a/tools/testing/selftests/timers/Makefile +++ b/tools/testing/selftests/timers/Makefile @@ -1,6 +1,6 @@ BUILD_FLAGS = -DKTEST CFLAGS += -O3 -Wl,-no-as-needed -Wall $(BUILD_FLAGS) -LDFLAGS += -lrt -lpthread +LDFLAGS += -lrt -lpthread -lm # these are all "safe" tests that don't modify # system time or require escalated privileges @@ -8,7 +8,7 @@ TEST_GEN_PROGS = posix_timers nanosleep nsleep-lat set-timer-lat mqueue-lat \ inconsistency-check raw_skew threadtest rtctest TEST_GEN_PROGS_EXTENDED = alarmtimer-suspend valid-adjtimex adjtick change_skew \ - skew_consistency clocksource-switch leap-a-day \ + skew_consistency clocksource-switch freq-step leap-a-day \ leapcrash set-tai set-2038 set-tz @@ -24,6 +24,7 @@ run_destructive_tests: run_tests ./change_skew ./skew_consistency ./clocksource-switch + ./freq-step ./leap-a-day -s -i 10 ./leapcrash ./set-tz diff --git a/tools/testing/selftests/timers/freq-step.c b/tools/testing/selftests/timers/freq-step.c new file mode 100644 index 000000000000..e8c61830825a --- /dev/null +++ b/tools/testing/selftests/timers/freq-step.c @@ -0,0 +1,268 @@ +/* + * This test checks the response of the system clock to frequency + * steps made with adjtimex(). The frequency error and stability of + * the CLOCK_MONOTONIC clock relative to the CLOCK_MONOTONIC_RAW clock + * is measured in two intervals following the step. The test fails if + * values from the second interval exceed specified limits. + * + * Copyright (C) Miroslav Lichvar 2017 + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of version 2 of the GNU General Public License as + * published by the Free Software Foundation. + * + * 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 +#include +#include +#include +#include + +#include "../kselftest.h" + +#define SAMPLES 100 +#define SAMPLE_READINGS 10 +#define MEAN_SAMPLE_INTERVAL 0.1 +#define STEP_INTERVAL 1.0 +#define MAX_PRECISION 100e-9 +#define MAX_FREQ_ERROR 10e-6 +#define MAX_STDDEV 1000e-9 + +struct sample { + double offset; + double time; +}; + +static time_t mono_raw_base; +static time_t mono_base; +static long user_hz; +static double precision; +static double mono_freq_offset; + +static double diff_timespec(struct timespec *ts1, struct timespec *ts2) +{ + return ts1->tv_sec - ts2->tv_sec + (ts1->tv_nsec - ts2->tv_nsec) / 1e9; +} + +static double get_sample(struct sample *sample) +{ + double delay, mindelay = 0.0; + struct timespec ts1, ts2, ts3; + int i; + + for (i = 0; i < SAMPLE_READINGS; i++) { + clock_gettime(CLOCK_MONOTONIC_RAW, &ts1); + clock_gettime(CLOCK_MONOTONIC, &ts2); + clock_gettime(CLOCK_MONOTONIC_RAW, &ts3); + + ts1.tv_sec -= mono_raw_base; + ts2.tv_sec -= mono_base; + ts3.tv_sec -= mono_raw_base; + + delay = diff_timespec(&ts3, &ts1); + if (delay <= 1e-9) { + i--; + continue; + } + + if (!i || delay < mindelay) { + sample->offset = diff_timespec(&ts2, &ts1); + sample->offset -= delay / 2.0; + sample->time = ts1.tv_sec + ts1.tv_nsec / 1e9; + mindelay = delay; + } + } + + return mindelay; +} + +static void reset_ntp_error(void) +{ + struct timex txc; + + txc.modes = ADJ_SETOFFSET; + txc.time.tv_sec = 0; + txc.time.tv_usec = 0; + + if (adjtimex(&txc) < 0) { + perror("[FAIL] adjtimex"); + ksft_exit_fail(); + } +} + +static void set_frequency(double freq) +{ + struct timex txc; + int tick_offset; + + tick_offset = 1e6 * freq / user_hz; + + txc.modes = ADJ_TICK | ADJ_FREQUENCY; + txc.tick = 1000000 / user_hz + tick_offset; + txc.freq = (1e6 * freq - user_hz * tick_offset) * (1 << 16); + + if (adjtimex(&txc) < 0) { + perror("[FAIL] adjtimex"); + ksft_exit_fail(); + } +} + +static void regress(struct sample *samples, int n, double *intercept, + double *slope, double *r_stddev, double *r_max) +{ + double x, y, r, x_sum, y_sum, xy_sum, x2_sum, r2_sum; + int i; + + x_sum = 0.0, y_sum = 0.0, xy_sum = 0.0, x2_sum = 0.0; + + for (i = 0; i < n; i++) { + x = samples[i].time; + y = samples[i].offset; + + x_sum += x; + y_sum += y; + xy_sum += x * y; + x2_sum += x * x; + } + + *slope = (xy_sum - x_sum * y_sum / n) / (x2_sum - x_sum * x_sum / n); + *intercept = (y_sum - *slope * x_sum) / n; + + *r_max = 0.0, r2_sum = 0.0; + + for (i = 0; i < n; i++) { + x = samples[i].time; + y = samples[i].offset; + r = fabs(x * *slope + *intercept - y); + if (*r_max < r) + *r_max = r; + r2_sum += r * r; + } + + *r_stddev = sqrt(r2_sum / n); +} + +static int run_test(int calibration, double freq_base, double freq_step) +{ + struct sample samples[SAMPLES]; + double intercept, slope, stddev1, max1, stddev2, max2; + double freq_error1, freq_error2; + int i; + + set_frequency(freq_base); + + for (i = 0; i < 10; i++) + usleep(1e6 * MEAN_SAMPLE_INTERVAL / 10); + + reset_ntp_error(); + + set_frequency(freq_base + freq_step); + + for (i = 0; i < 10; i++) + usleep(rand() % 2000000 * STEP_INTERVAL / 10); + + set_frequency(freq_base); + + for (i = 0; i < SAMPLES; i++) { + usleep(rand() % 2000000 * MEAN_SAMPLE_INTERVAL); + get_sample(&samples[i]); + } + + if (calibration) { + regress(samples, SAMPLES, &intercept, &slope, &stddev1, &max1); + mono_freq_offset = slope; + printf("CLOCK_MONOTONIC_RAW frequency offset: %11.3f ppm\n", + 1e6 * mono_freq_offset); + return 0; + } + + regress(samples, SAMPLES / 2, &intercept, &slope, &stddev1, &max1); + freq_error1 = slope * (1.0 - mono_freq_offset) - mono_freq_offset - + freq_base; + + regress(samples + SAMPLES / 2, SAMPLES / 2, &intercept, &slope, + &stddev2, &max2); + freq_error2 = slope * (1.0 - mono_freq_offset) - mono_freq_offset - + freq_base; + + printf("%6.0f %+10.3f %6.0f %7.0f %+10.3f %6.0f %7.0f\t", + 1e6 * freq_step, + 1e6 * freq_error1, 1e9 * stddev1, 1e9 * max1, + 1e6 * freq_error2, 1e9 * stddev2, 1e9 * max2); + + if (fabs(freq_error2) > MAX_FREQ_ERROR || stddev2 > MAX_STDDEV) { + printf("[FAIL]\n"); + return 1; + } + + printf("[OK]\n"); + return 0; +} + +static void init_test(void) +{ + struct timespec ts; + struct sample sample; + + if (clock_gettime(CLOCK_MONOTONIC_RAW, &ts)) { + perror("[FAIL] clock_gettime(CLOCK_MONOTONIC_RAW)"); + ksft_exit_fail(); + } + + mono_raw_base = ts.tv_sec; + + if (clock_gettime(CLOCK_MONOTONIC, &ts)) { + perror("[FAIL] clock_gettime(CLOCK_MONOTONIC)"); + ksft_exit_fail(); + } + + mono_base = ts.tv_sec; + + user_hz = sysconf(_SC_CLK_TCK); + + precision = get_sample(&sample) / 2.0; + printf("CLOCK_MONOTONIC_RAW+CLOCK_MONOTONIC precision: %.0f ns\t\t", + 1e9 * precision); + + if (precision > MAX_PRECISION) { + printf("[SKIP]\n"); + ksft_exit_skip(); + } + + printf("[OK]\n"); + srand(ts.tv_sec ^ ts.tv_nsec); + + run_test(1, 0.0, 0.0); +} + +int main(int argc, char **argv) +{ + double freq_base, freq_step; + int i, j, fails = 0; + + init_test(); + + printf("Checking response to frequency step:\n"); + printf(" Step 1st interval 2nd interval\n"); + printf(" Freq Dev Max Freq Dev Max\n"); + + for (i = 2; i >= 0; i--) { + for (j = 0; j < 5; j++) { + freq_base = (rand() % (1 << 24) - (1 << 23)) / 65536e6; + freq_step = 10e-6 * (1 << (6 * i)); + fails += run_test(0, freq_base, freq_step); + } + } + + set_frequency(0.0); + + if (fails) + ksft_exit_fail(); + + ksft_exit_pass(); +} -- cgit