From 0fb71d340d355156818bb53eb36ae79a3f88bda9 Mon Sep 17 00:00:00 2001 From: Minfei Huang Date: Mon, 25 Apr 2016 17:20:28 +0800 Subject: clocksource: Make clocksource insert entry more efficient In clocksource_enqueue(), it is unnecessary to continue looping the list, if we find there is an entry that the value of rating is smaller than the new one. It is safe to be out the loop, because all of entry are inserted in descending order. Cc: Prarit Bhargava Cc: Richard Cochran Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Minfei Huang Signed-off-by: John Stultz --- kernel/time/clocksource.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index 56ece145a814..6a5a310a1a53 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -669,10 +669,12 @@ static void clocksource_enqueue(struct clocksource *cs) struct list_head *entry = &clocksource_list; struct clocksource *tmp; - list_for_each_entry(tmp, &clocksource_list, list) + list_for_each_entry(tmp, &clocksource_list, list) { /* Keep track of the place, where to insert */ - if (tmp->rating >= cs->rating) - entry = &tmp->list; + if (tmp->rating < cs->rating) + break; + entry = &tmp->list; + } list_add(&cs->list, entry); } -- cgit v1.2.3-59-g8ed1b From 0209b937569a133dedfe930cdfff3a0d1d68c9e9 Mon Sep 17 00:00:00 2001 From: Thomas Graziadei Date: Tue, 31 May 2016 15:06:06 +0200 Subject: timekeeping: Fix 1ns/tick drift with GENERIC_TIME_VSYSCALL_OLD The user notices the problem in a raw and real time drift, calling clock_gettime with CLOCK_REALTIME / CLOCK_MONOTONIC_RAW on a system with no ntp correction taking place (no ntpd or ptp stuff running). The problem is, that old_vsyscall_fixup adds an extra 1ns even though xtime_nsec is already held in full nsecs and the remainder in this case is 0. Do the rounding up buisness only if needed. Cc: Prarit Bhargava Cc: Richard Cochran Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Thomas Graziadei Signed-off-by: John Stultz --- kernel/time/timekeeping.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 479d25cd3d4f..a196e08324e7 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -480,10 +480,12 @@ static inline void old_vsyscall_fixup(struct timekeeper *tk) * users are removed, this can be killed. */ remainder = tk->tkr_mono.xtime_nsec & ((1ULL << tk->tkr_mono.shift) - 1); - tk->tkr_mono.xtime_nsec -= remainder; - tk->tkr_mono.xtime_nsec += 1ULL << tk->tkr_mono.shift; - tk->ntp_error += remainder << tk->ntp_error_shift; - tk->ntp_error -= (1ULL << tk->tkr_mono.shift) << tk->ntp_error_shift; + if (remainder != 0) { + tk->tkr_mono.xtime_nsec -= remainder; + tk->tkr_mono.xtime_nsec += 1ULL << tk->tkr_mono.shift; + tk->ntp_error += remainder << tk->ntp_error_shift; + tk->ntp_error -= (1ULL << tk->tkr_mono.shift) << tk->ntp_error_shift; + } } #else #define old_vsyscall_fixup(tk) -- cgit v1.2.3-59-g8ed1b From af4afb40085f04f8b2ea8d28df878f7f0be02f89 Mon Sep 17 00:00:00 2001 From: Pratyush Patel Date: Tue, 14 Jun 2016 11:00:42 +0200 Subject: alarmtimer: Fix comments describing structure fields Updated struct alarm and struct alarm_timer descriptions. Cc: Prarit Bhargava Cc: Richard Cochran Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Pratyush Patel Signed-off-by: John Stultz --- include/linux/alarmtimer.h | 6 +++--- kernel/time/alarmtimer.c | 1 - 2 files changed, 3 insertions(+), 4 deletions(-) (limited to 'kernel/time') diff --git a/include/linux/alarmtimer.h b/include/linux/alarmtimer.h index 52f3b7da4f2d..9d8031257a90 100644 --- a/include/linux/alarmtimer.h +++ b/include/linux/alarmtimer.h @@ -26,10 +26,10 @@ enum alarmtimer_restart { * struct alarm - Alarm timer structure * @node: timerqueue node for adding to the event list this value * also includes the expiration time. - * @period: Period for recuring alarms + * @timer: hrtimer used to schedule events while running * @function: Function pointer to be executed when the timer fires. - * @type: Alarm type (BOOTTIME/REALTIME) - * @enabled: Flag that represents if the alarm is set to fire or not + * @type: Alarm type (BOOTTIME/REALTIME). + * @state: Flag that represents if the alarm is set to fire or not. * @data: Internal data value. */ struct alarm { diff --git a/kernel/time/alarmtimer.c b/kernel/time/alarmtimer.c index e840ed867a5d..c3aad685bbc0 100644 --- a/kernel/time/alarmtimer.c +++ b/kernel/time/alarmtimer.c @@ -30,7 +30,6 @@ * struct alarm_base - Alarm timer bases * @lock: Lock for syncrhonized access to the base * @timerqueue: Timerqueue head managing the list of events - * @timer: hrtimer used to schedule events while running * @gettime: Function to read the time correlating to the base * @base_clockid: clockid for the base */ -- cgit v1.2.3-59-g8ed1b From e6c2682a1da36a2e79d9bab470412374434ce89e Mon Sep 17 00:00:00 2001 From: Deepa Dinamani Date: Wed, 8 Jun 2016 22:04:59 -0700 Subject: time: Add time64_to_tm() time_to_tm() takes time_t as an argument. time_t is not y2038 safe. Add time64_to_tm() that takes time64_t as an argument which is y2038 safe. The plan is to eventually replace all calls to time_to_tm() by time64_to_tm(). Cc: Prarit Bhargava Cc: Richard Cochran Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Deepa Dinamani Signed-off-by: John Stultz --- include/linux/time.h | 15 ++++++++++++++- kernel/time/timeconv.c | 11 ++++++----- 2 files changed, 20 insertions(+), 6 deletions(-) (limited to 'kernel/time') diff --git a/include/linux/time.h b/include/linux/time.h index 297f09f23896..4cea09d94208 100644 --- a/include/linux/time.h +++ b/include/linux/time.h @@ -205,7 +205,20 @@ struct tm { int tm_yday; }; -void time_to_tm(time_t totalsecs, int offset, struct tm *result); +void time64_to_tm(time64_t totalsecs, int offset, struct tm *result); + +/** + * time_to_tm - converts the calendar time to local broken-down time + * + * @totalsecs the number of seconds elapsed since 00:00:00 on January 1, 1970, + * Coordinated Universal Time (UTC). + * @offset offset seconds adding to totalsecs. + * @result pointer to struct tm variable to receive broken-down time + */ +static inline void time_to_tm(time_t totalsecs, int offset, struct tm *result) +{ + time64_to_tm(totalsecs, offset, result); +} /** * timespec_to_ns - Convert timespec to nanoseconds diff --git a/kernel/time/timeconv.c b/kernel/time/timeconv.c index 86628e755f38..7142580ad94f 100644 --- a/kernel/time/timeconv.c +++ b/kernel/time/timeconv.c @@ -67,20 +67,21 @@ static const unsigned short __mon_yday[2][13] = { #define SECS_PER_DAY (SECS_PER_HOUR * 24) /** - * time_to_tm - converts the calendar time to local broken-down time + * time64_to_tm - converts the calendar time to local broken-down time * * @totalsecs the number of seconds elapsed since 00:00:00 on January 1, 1970, * Coordinated Universal Time (UTC). * @offset offset seconds adding to totalsecs. * @result pointer to struct tm variable to receive broken-down time */ -void time_to_tm(time_t totalsecs, int offset, struct tm *result) +void time64_to_tm(time64_t totalsecs, int offset, struct tm *result) { long days, rem, y; + int remainder; const unsigned short *ip; - days = totalsecs / SECS_PER_DAY; - rem = totalsecs % SECS_PER_DAY; + days = div_s64_rem(totalsecs, SECS_PER_DAY, &remainder); + rem = remainder; rem += offset; while (rem < 0) { rem += SECS_PER_DAY; @@ -124,4 +125,4 @@ void time_to_tm(time_t totalsecs, int offset, struct tm *result) result->tm_mon = y; result->tm_mday = days + 1; } -EXPORT_SYMBOL(time_to_tm); +EXPORT_SYMBOL(time64_to_tm); -- cgit v1.2.3-59-g8ed1b From 4a19bd3d22d51a0c89db10879dacaffa0f52aecf Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 17 Jun 2016 18:03:02 +0200 Subject: time: Avoid timespec in udelay_test udelay_test_single() uses ktime_get_ts() to get two timespec values and calculate the difference between them, while udelay_test_show() uses the same to printk() the current monotonic time. Both of these are y2038 safe on all machines, but we want to get rid of struct timespec anyway, so this converts the code to use ktime_get_ns() and ktime_get_ts64() respectively. Cc: Prarit Bhargava Cc: Richard Cochran Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Arnd Bergmann Signed-off-by: John Stultz --- kernel/time/test_udelay.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/test_udelay.c b/kernel/time/test_udelay.c index e622ba365a13..b0928ab3270f 100644 --- a/kernel/time/test_udelay.c +++ b/kernel/time/test_udelay.c @@ -43,13 +43,13 @@ static int udelay_test_single(struct seq_file *s, int usecs, uint32_t iters) int allowed_error_ns = usecs * 5; for (i = 0; i < iters; ++i) { - struct timespec ts1, ts2; + s64 kt1, kt2; int time_passed; - ktime_get_ts(&ts1); + kt1 = ktime_get_ns(); udelay(usecs); - ktime_get_ts(&ts2); - time_passed = timespec_to_ns(&ts2) - timespec_to_ns(&ts1); + kt2 = ktime_get_ns(); + time_passed = kt2 - kt1; if (i == 0 || time_passed < min) min = time_passed; @@ -87,11 +87,11 @@ static int udelay_test_show(struct seq_file *s, void *v) if (usecs > 0 && iters > 0) { return udelay_test_single(s, usecs, iters); } else if (usecs == 0) { - struct timespec ts; + struct timespec64 ts; - ktime_get_ts(&ts); - seq_printf(s, "udelay() test (lpj=%ld kt=%ld.%09ld)\n", - loops_per_jiffy, ts.tv_sec, ts.tv_nsec); + ktime_get_ts64(&ts); + seq_printf(s, "udelay() test (lpj=%ld kt=%lld.%09ld)\n", + loops_per_jiffy, (s64)ts.tv_sec, ts.tv_nsec); seq_puts(s, "usage:\n"); seq_puts(s, "echo USECS [ITERS] > " DEBUGFS_FILENAME "\n"); seq_puts(s, "cat " DEBUGFS_FILENAME "\n"); -- cgit v1.2.3-59-g8ed1b From 7c71feb0a6766c7c3a262e3cc33ae231f3953cb6 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Fri, 17 Jun 2016 17:30:47 +0200 Subject: timer: Avoid using timespec The tstats_show() function prints a ktime_t variable by converting it to struct timespec first. The algorithm is ok, but we want to stop using timespec in general because of the 32-bit time_t overflow problem. This changes the code to use struct timespec64, without any functional change. Cc: Prarit Bhargava Cc: Richard Cochran Cc: Thomas Gleixner Cc: Ingo Molnar Signed-off-by: Arnd Bergmann Signed-off-by: John Stultz --- kernel/time/timer_stats.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'kernel/time') diff --git a/kernel/time/timer_stats.c b/kernel/time/timer_stats.c index 1adecb4b87c8..087204c733eb 100644 --- a/kernel/time/timer_stats.c +++ b/kernel/time/timer_stats.c @@ -279,7 +279,7 @@ static void print_name_offset(struct seq_file *m, unsigned long addr) static int tstats_show(struct seq_file *m, void *v) { - struct timespec period; + struct timespec64 period; struct entry *entry; unsigned long ms; long events = 0; @@ -295,11 +295,11 @@ static int tstats_show(struct seq_file *m, void *v) time = ktime_sub(time_stop, time_start); - period = ktime_to_timespec(time); + period = ktime_to_timespec64(time); ms = period.tv_nsec / 1000000; seq_puts(m, "Timer Stats Version: v0.3\n"); - seq_printf(m, "Sample period: %ld.%03ld s\n", period.tv_sec, ms); + seq_printf(m, "Sample period: %ld.%03ld s\n", (long)period.tv_sec, ms); if (atomic_read(&overflow_count)) seq_printf(m, "Overflow: %d entries\n", atomic_read(&overflow_count)); seq_printf(m, "Collection: %s\n", timer_stats_active ? "active" : "inactive"); -- cgit v1.2.3-59-g8ed1b