Merge branch 'fortglx/4.13/time' of https://git.linaro.org/people/john.stultz/linux into timers/core

Merge time(keeping) updates from John Stultz:

  "Just a small set of changes, the biggest changes being the MONOTONIC_RAW
   handling cleanup, and a new kselftest from Miroslav. Also a a clear
   warning deprecating CONFIG_GENERIC_TIME_VSYSCALL_OLD, which affects ppc
   and ia64."

arch/arm64/kernel/vdso.c

@@ -220,10 +220,8 @@ void update_vsyscall(struct timekeeper *tk)
 	if (!use_syscall) {
 		/* tkr_mono.cycle_last == tkr_raw.cycle_last */
 		vdso_data->cs_cycle_last	= tk->tkr_mono.cycle_last;
-		vdso_data->raw_time_sec		= tk->raw_time.tv_sec;
-		vdso_data->raw_time_nsec	= (tk->raw_time.tv_nsec <<
-						   tk->tkr_raw.shift) +
-						  tk->tkr_raw.xtime_nsec;
+		vdso_data->raw_time_sec         = tk->raw_sec;
+		vdso_data->raw_time_nsec        = tk->tkr_raw.xtime_nsec;
 		vdso_data->xtime_clock_sec	= tk->xtime_sec;
 		vdso_data->xtime_clock_nsec	= tk->tkr_mono.xtime_nsec;
 		vdso_data->cs_mono_mult		= tk->tkr_mono.mult;

include/linux/timekeeper_internal.h

@@ -51,7 +51,7 @@ struct tk_read_base {
  * @clock_was_set_seq:	The sequence number of clock was set events
  * @cs_was_changed_seq:	The sequence number of clocksource change events
  * @next_leap_ktime:	CLOCK_MONOTONIC time value of a pending leap-second
- * @raw_time:		Monotonic raw base time in timespec64 format
+ * @raw_sec:		CLOCK_MONOTONIC_RAW  time in seconds
  * @cycle_interval:	Number of clock cycles in one NTP interval
  * @xtime_interval:	Number of clock shifted nano seconds in one NTP
  *			interval.
@@ -93,7 +93,7 @@ struct timekeeper {
 	unsigned int		clock_was_set_seq;
 	u8			cs_was_changed_seq;
 	ktime_t			next_leap_ktime;
-	struct timespec64	raw_time;
+	u64			raw_sec;
 
 	/* The following members are for timekeeping internal use */
 	u64			cycle_interval;

kernel/time/timekeeping.c

@@ -72,6 +72,10 @@ static inline void tk_normalize_xtime(struct timekeeper *tk)
 		tk->tkr_mono.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_mono.shift;
 		tk->xtime_sec++;
 	}
+	while (tk->tkr_raw.xtime_nsec >= ((u64)NSEC_PER_SEC << tk->tkr_raw.shift)) {
+		tk->tkr_raw.xtime_nsec -= (u64)NSEC_PER_SEC << tk->tkr_raw.shift;
+		tk->raw_sec++;
+	}
 }
 
 static inline struct timespec64 tk_xtime(struct timekeeper *tk)
@@ -285,12 +289,14 @@ static void tk_setup_internals(struct timekeeper *tk, struct clocksource *clock)
 	 /* if changing clocks, convert xtime_nsec shift units */
 	if (old_clock) {
 		int shift_change = clock->shift - old_clock->shift;
-		if (shift_change < 0)
+		if (shift_change < 0) {
 			tk->tkr_mono.xtime_nsec >>= -shift_change;
-		else
+			tk->tkr_raw.xtime_nsec >>= -shift_change;
+		} else {
 			tk->tkr_mono.xtime_nsec <<= shift_change;
+			tk->tkr_raw.xtime_nsec <<= shift_change;
+		}
 	}
-	tk->tkr_raw.xtime_nsec = 0;
 
 	tk->tkr_mono.shift = clock->shift;
 	tk->tkr_raw.shift = clock->shift;
@@ -510,6 +516,7 @@ static void halt_fast_timekeeper(struct timekeeper *tk)
 }
 
 #ifdef CONFIG_GENERIC_TIME_VSYSCALL_OLD
+#warning Please contact your maintainers, as GENERIC_TIME_VSYSCALL_OLD compatibity will disappear soon.
 
 static inline void update_vsyscall(struct timekeeper *tk)
 {
@@ -619,9 +626,6 @@ static inline void tk_update_ktime_data(struct timekeeper *tk)
 	nsec = (u32) tk->wall_to_monotonic.tv_nsec;
 	tk->tkr_mono.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec);
 
-	/* Update the monotonic raw base */
-	tk->tkr_raw.base = timespec64_to_ktime(tk->raw_time);
-
 	/*
 	 * The sum of the nanoseconds portions of xtime and
 	 * wall_to_monotonic can be greater/equal one second. Take
@@ -631,6 +635,11 @@ static inline void tk_update_ktime_data(struct timekeeper *tk)
 	if (nsec >= NSEC_PER_SEC)
 		seconds++;
 	tk->ktime_sec = seconds;
+
+	/* Update the monotonic raw base */
+	seconds = tk->raw_sec;
+	nsec = (u32)(tk->tkr_raw.xtime_nsec >> tk->tkr_raw.shift);
+	tk->tkr_raw.base = ns_to_ktime(seconds * NSEC_PER_SEC + nsec);
 }
 
 /* must hold timekeeper_lock */
@@ -672,7 +681,6 @@ static void timekeeping_update(struct timekeeper *tk, unsigned int action)
 static void timekeeping_forward_now(struct timekeeper *tk)
 {
 	u64 cycle_now, delta;
-	u64 nsec;
 
 	cycle_now = tk_clock_read(&tk->tkr_mono);
 	delta = clocksource_delta(cycle_now, tk->tkr_mono.cycle_last, tk->tkr_mono.mask);
@@ -684,10 +692,13 @@ static void timekeeping_forward_now(struct timekeeper *tk)
 	/* If arch requires, add in get_arch_timeoffset() */
 	tk->tkr_mono.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_mono.shift;
 
-	tk_normalize_xtime(tk);
 
-	nsec = clocksource_cyc2ns(delta, tk->tkr_raw.mult, tk->tkr_raw.shift);
-	timespec64_add_ns(&tk->raw_time, nsec);
+	tk->tkr_raw.xtime_nsec += delta * tk->tkr_raw.mult;
+
+	/* If arch requires, add in get_arch_timeoffset() */
+	tk->tkr_raw.xtime_nsec += (u64)arch_gettimeoffset() << tk->tkr_raw.shift;
+
+	tk_normalize_xtime(tk);
 }
 
 /**
@@ -1373,19 +1384,18 @@ int timekeeping_notify(struct clocksource *clock)
 void getrawmonotonic64(struct timespec64 *ts)
 {
 	struct timekeeper *tk = &tk_core.timekeeper;
-	struct timespec64 ts64;
 	unsigned long seq;
 	u64 nsecs;
 
 	do {
 		seq = read_seqcount_begin(&tk_core.seq);
+		ts->tv_sec = tk->raw_sec;
 		nsecs = timekeeping_get_ns(&tk->tkr_raw);
-		ts64 = tk->raw_time;
 
 	} while (read_seqcount_retry(&tk_core.seq, seq));
 
-	timespec64_add_ns(&ts64, nsecs);
-	*ts = ts64;
+	ts->tv_nsec = 0;
+	timespec64_add_ns(ts, nsecs);
 }
 EXPORT_SYMBOL(getrawmonotonic64);
 
@@ -1509,8 +1519,7 @@ void __init timekeeping_init(void)
 	tk_setup_internals(tk, clock);
 
 	tk_set_xtime(tk, &now);
-	tk->raw_time.tv_sec = 0;
-	tk->raw_time.tv_nsec = 0;
+	tk->raw_sec = 0;
 	if (boot.tv_sec == 0 && boot.tv_nsec == 0)
 		boot = tk_xtime(tk);
 
@@ -2011,15 +2020,12 @@ static u64 logarithmic_accumulation(struct timekeeper *tk, u64 offset,
 	*clock_set |= accumulate_nsecs_to_secs(tk);
 
 	/* Accumulate raw time */
-	tk->tkr_raw.xtime_nsec += (u64)tk->raw_time.tv_nsec << tk->tkr_raw.shift;
 	tk->tkr_raw.xtime_nsec += tk->raw_interval << shift;
 	snsec_per_sec = (u64)NSEC_PER_SEC << tk->tkr_raw.shift;
 	while (tk->tkr_raw.xtime_nsec >= snsec_per_sec) {
 		tk->tkr_raw.xtime_nsec -= snsec_per_sec;
-		tk->raw_time.tv_sec++;
+		tk->raw_sec++;
 	}
-	tk->raw_time.tv_nsec = tk->tkr_raw.xtime_nsec >> tk->tkr_raw.shift;
-	tk->tkr_raw.xtime_nsec -= (u64)tk->raw_time.tv_nsec << tk->tkr_raw.shift;
 
 	/* Accumulate error between NTP and clock interval */
 	tk->ntp_error += tk->ntp_tick << shift;

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

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 <mlichvar@redhat.com>  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 <math.h>
+#include <stdio.h>
+#include <sys/timex.h>
+#include <time.h>
+#include <unistd.h>
+
+#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();
+}

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);