[GIT PULL] time/r tree changes for v3.20

From: Ingo Molnar
Date: Mon Feb 09 2015 - 04:10:37 EST


Linus,

Please pull the latest timers-core-for-linus git tree from:

git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers-core-for-linus

# HEAD: 4ebbda5251374d532ba8939de4241d769d1420b6 hrtimer: Make __hrtimer_get_next_event() static

The main changes in this cycle were:

- rework hrtimer expiry calculation in hrtimer_interrupt():
the previous code had a subtle bug where expiry caching
would miss an expiry, resulting in occasional bogus
(late) expiry of hrtimers.

- continuing Y2038 fixes

- ktime division optimization

- misc smaller fixes and cleanups

Thanks,

Ingo

------------------>
Chunyan Zhang (1):
ktime.h: Introduce ktime_ms_delta

John Stultz (2):
time: Expose getboottime64 for in-kernel uses
time: Expose get_monotonic_boottime64 for in-kernel use

Nicolas Pitre (1):
ktime: Optimize ktime_divns for constant divisors

Thomas Gleixner (1):
hrtimer: Prevent stale expiry time in hrtimer_interrupt()

Xunlei Pang (5):
rtc: Update interface.c to use y2038-safe time interfaces
rtc: Update rtc-dev to use y2038-safe time interfaces
rtc: Modify rtc_hctosys() to address y2038 issues
rtc: Remove redundant rtc_valid_tm() from rtc_hctosys()
rtc: Convert rtc_set_ntp_time() to use timespec64

kbuild test robot (1):
hrtimer: Make __hrtimer_get_next_event() static


drivers/rtc/hctosys.c | 18 ++-----
drivers/rtc/interface.c | 22 ++++-----
drivers/rtc/rtc-dev.c | 8 ++--
drivers/rtc/systohc.c | 6 +--
include/linux/hrtimer.h | 2 +
include/linux/ktime.h | 17 ++++++-
include/linux/rtc.h | 2 +-
include/linux/timekeeping.h | 21 ++++++++-
kernel/time/hrtimer.c | 112 ++++++++++++++++++++------------------------
kernel/time/ntp.c | 4 +-
kernel/time/timekeeping.c | 12 ++---
11 files changed, 120 insertions(+), 104 deletions(-)

diff --git a/drivers/rtc/hctosys.c b/drivers/rtc/hctosys.c
index 4aa60d74004e..6c719f23520a 100644
--- a/drivers/rtc/hctosys.c
+++ b/drivers/rtc/hctosys.c
@@ -26,7 +26,7 @@ static int __init rtc_hctosys(void)
{
int err = -ENODEV;
struct rtc_time tm;
- struct timespec tv = {
+ struct timespec64 tv64 = {
.tv_nsec = NSEC_PER_SEC >> 1,
};
struct rtc_device *rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
@@ -45,25 +45,17 @@ static int __init rtc_hctosys(void)

}

- err = rtc_valid_tm(&tm);
- if (err) {
- dev_err(rtc->dev.parent,
- "hctosys: invalid date/time\n");
- goto err_invalid;
- }
-
- rtc_tm_to_time(&tm, &tv.tv_sec);
+ tv64.tv_sec = rtc_tm_to_time64(&tm);

- err = do_settimeofday(&tv);
+ err = do_settimeofday64(&tv64);

dev_info(rtc->dev.parent,
"setting system clock to "
- "%d-%02d-%02d %02d:%02d:%02d UTC (%u)\n",
+ "%d-%02d-%02d %02d:%02d:%02d UTC (%lld)\n",
tm.tm_year + 1900, tm.tm_mon + 1, tm.tm_mday,
tm.tm_hour, tm.tm_min, tm.tm_sec,
- (unsigned int) tv.tv_sec);
+ (long long) tv64.tv_sec);

-err_invalid:
err_read:
rtc_class_close(rtc);

diff --git a/drivers/rtc/interface.c b/drivers/rtc/interface.c
index 45bfc28ee3aa..37215cf983e9 100644
--- a/drivers/rtc/interface.c
+++ b/drivers/rtc/interface.c
@@ -73,10 +73,8 @@ int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm)
else if (rtc->ops->set_time)
err = rtc->ops->set_time(rtc->dev.parent, tm);
else if (rtc->ops->set_mmss) {
- unsigned long secs;
- err = rtc_tm_to_time(tm, &secs);
- if (err == 0)
- err = rtc->ops->set_mmss(rtc->dev.parent, secs);
+ time64_t secs64 = rtc_tm_to_time64(tm);
+ err = rtc->ops->set_mmss(rtc->dev.parent, secs64);
} else
err = -EINVAL;

@@ -105,7 +103,7 @@ int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs)

err = rtc->ops->read_time(rtc->dev.parent, &old);
if (err == 0) {
- rtc_time_to_tm(secs, &new);
+ rtc_time64_to_tm(secs, &new);

/*
* avoid writing when we're going to change the day of
@@ -157,7 +155,7 @@ int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
int err;
struct rtc_time before, now;
int first_time = 1;
- unsigned long t_now, t_alm;
+ time64_t t_now, t_alm;
enum { none, day, month, year } missing = none;
unsigned days;

@@ -258,8 +256,8 @@ int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
}

/* with luck, no rollover is needed */
- rtc_tm_to_time(&now, &t_now);
- rtc_tm_to_time(&alarm->time, &t_alm);
+ t_now = rtc_tm_to_time64(&now);
+ t_alm = rtc_tm_to_time64(&alarm->time);
if (t_now < t_alm)
goto done;

@@ -273,7 +271,7 @@ int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
case day:
dev_dbg(&rtc->dev, "alarm rollover: %s\n", "day");
t_alm += 24 * 60 * 60;
- rtc_time_to_tm(t_alm, &alarm->time);
+ rtc_time64_to_tm(t_alm, &alarm->time);
break;

/* Month rollover ... if it's the 31th, an alarm on the 3rd will
@@ -346,19 +344,19 @@ EXPORT_SYMBOL_GPL(rtc_read_alarm);
static int __rtc_set_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm)
{
struct rtc_time tm;
- long now, scheduled;
+ time64_t now, scheduled;
int err;

err = rtc_valid_tm(&alarm->time);
if (err)
return err;
- rtc_tm_to_time(&alarm->time, &scheduled);
+ scheduled = rtc_tm_to_time64(&alarm->time);

/* Make sure we're not setting alarms in the past */
err = __rtc_read_time(rtc, &tm);
if (err)
return err;
- rtc_tm_to_time(&tm, &now);
+ now = rtc_tm_to_time64(&tm);
if (scheduled <= now)
return -ETIME;
/*
diff --git a/drivers/rtc/rtc-dev.c b/drivers/rtc/rtc-dev.c
index d04939369251..799c34bcb26f 100644
--- a/drivers/rtc/rtc-dev.c
+++ b/drivers/rtc/rtc-dev.c
@@ -304,12 +304,12 @@ static long rtc_dev_ioctl(struct file *file,
* Not supported here.
*/
{
- unsigned long now, then;
+ time64_t now, then;

err = rtc_read_time(rtc, &tm);
if (err < 0)
return err;
- rtc_tm_to_time(&tm, &now);
+ now = rtc_tm_to_time64(&tm);

alarm.time.tm_mday = tm.tm_mday;
alarm.time.tm_mon = tm.tm_mon;
@@ -317,11 +317,11 @@ static long rtc_dev_ioctl(struct file *file,
err = rtc_valid_tm(&alarm.time);
if (err < 0)
return err;
- rtc_tm_to_time(&alarm.time, &then);
+ then = rtc_tm_to_time64(&alarm.time);

/* alarm may need to wrap into tomorrow */
if (then < now) {
- rtc_time_to_tm(now + 24 * 60 * 60, &tm);
+ rtc_time64_to_tm(now + 24 * 60 * 60, &tm);
alarm.time.tm_mday = tm.tm_mday;
alarm.time.tm_mon = tm.tm_mon;
alarm.time.tm_year = tm.tm_year;
diff --git a/drivers/rtc/systohc.c b/drivers/rtc/systohc.c
index bf3e242ccc5c..eb71872d0361 100644
--- a/drivers/rtc/systohc.c
+++ b/drivers/rtc/systohc.c
@@ -20,16 +20,16 @@
*
* If temporary failure is indicated the caller should try again 'soon'
*/
-int rtc_set_ntp_time(struct timespec now)
+int rtc_set_ntp_time(struct timespec64 now)
{
struct rtc_device *rtc;
struct rtc_time tm;
int err = -ENODEV;

if (now.tv_nsec < (NSEC_PER_SEC >> 1))
- rtc_time_to_tm(now.tv_sec, &tm);
+ rtc_time64_to_tm(now.tv_sec, &tm);
else
- rtc_time_to_tm(now.tv_sec + 1, &tm);
+ rtc_time64_to_tm(now.tv_sec + 1, &tm);

rtc = rtc_class_open(CONFIG_RTC_HCTOSYS_DEVICE);
if (rtc) {
diff --git a/include/linux/hrtimer.h b/include/linux/hrtimer.h
index a036d058a249..05f6df1fdf5b 100644
--- a/include/linux/hrtimer.h
+++ b/include/linux/hrtimer.h
@@ -170,6 +170,7 @@ enum hrtimer_base_type {
* @clock_was_set: Indicates that clock was set from irq context.
* @expires_next: absolute time of the next event which was scheduled
* via clock_set_next_event()
+ * @in_hrtirq: hrtimer_interrupt() is currently executing
* @hres_active: State of high resolution mode
* @hang_detected: The last hrtimer interrupt detected a hang
* @nr_events: Total number of hrtimer interrupt events
@@ -185,6 +186,7 @@ struct hrtimer_cpu_base {
unsigned int clock_was_set;
#ifdef CONFIG_HIGH_RES_TIMERS
ktime_t expires_next;
+ int in_hrtirq;
int hres_active;
int hang_detected;
unsigned long nr_events;
diff --git a/include/linux/ktime.h b/include/linux/ktime.h
index c9d645ad98ff..5fc3d1083071 100644
--- a/include/linux/ktime.h
+++ b/include/linux/ktime.h
@@ -166,7 +166,17 @@ static inline bool ktime_before(const ktime_t cmp1, const ktime_t cmp2)
}

#if BITS_PER_LONG < 64
-extern u64 ktime_divns(const ktime_t kt, s64 div);
+extern u64 __ktime_divns(const ktime_t kt, s64 div);
+static inline u64 ktime_divns(const ktime_t kt, s64 div)
+{
+ if (__builtin_constant_p(div) && !(div >> 32)) {
+ u64 ns = kt.tv64;
+ do_div(ns, div);
+ return ns;
+ } else {
+ return __ktime_divns(kt, div);
+ }
+}
#else /* BITS_PER_LONG < 64 */
# define ktime_divns(kt, div) (u64)((kt).tv64 / (div))
#endif
@@ -186,6 +196,11 @@ static inline s64 ktime_us_delta(const ktime_t later, const ktime_t earlier)
return ktime_to_us(ktime_sub(later, earlier));
}

+static inline s64 ktime_ms_delta(const ktime_t later, const ktime_t earlier)
+{
+ return ktime_to_ms(ktime_sub(later, earlier));
+}
+
static inline ktime_t ktime_add_us(const ktime_t kt, const u64 usec)
{
return ktime_add_ns(kt, usec * NSEC_PER_USEC);
diff --git a/include/linux/rtc.h b/include/linux/rtc.h
index 6d6be09a2fe5..dcad7ee0d746 100644
--- a/include/linux/rtc.h
+++ b/include/linux/rtc.h
@@ -161,7 +161,7 @@ extern void devm_rtc_device_unregister(struct device *dev,
extern int rtc_read_time(struct rtc_device *rtc, struct rtc_time *tm);
extern int rtc_set_time(struct rtc_device *rtc, struct rtc_time *tm);
extern int rtc_set_mmss(struct rtc_device *rtc, unsigned long secs);
-extern int rtc_set_ntp_time(struct timespec now);
+extern int rtc_set_ntp_time(struct timespec64 now);
int __rtc_read_alarm(struct rtc_device *rtc, struct rtc_wkalrm *alarm);
extern int rtc_read_alarm(struct rtc_device *rtc,
struct rtc_wkalrm *alrm);
diff --git a/include/linux/timekeeping.h b/include/linux/timekeeping.h
index 9b63d13ba82b..3eaae4754275 100644
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -33,6 +33,7 @@ extern time64_t ktime_get_real_seconds(void);

extern int __getnstimeofday64(struct timespec64 *tv);
extern void getnstimeofday64(struct timespec64 *tv);
+extern void getboottime64(struct timespec64 *ts);

#if BITS_PER_LONG == 64
/**
@@ -72,6 +73,11 @@ static inline struct timespec get_monotonic_coarse(void)
{
return get_monotonic_coarse64();
}
+
+static inline void getboottime(struct timespec *ts)
+{
+ return getboottime64(ts);
+}
#else
/**
* Deprecated. Use do_settimeofday64().
@@ -129,9 +135,15 @@ static inline struct timespec get_monotonic_coarse(void)
{
return timespec64_to_timespec(get_monotonic_coarse64());
}
-#endif

-extern void getboottime(struct timespec *ts);
+static inline void getboottime(struct timespec *ts)
+{
+ struct timespec64 ts64;
+
+ getboottime64(&ts64);
+ *ts = timespec64_to_timespec(ts64);
+}
+#endif

#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
#define ktime_get_real_ts64(ts) getnstimeofday64(ts)
@@ -217,6 +229,11 @@ static inline void get_monotonic_boottime(struct timespec *ts)
*ts = ktime_to_timespec(ktime_get_boottime());
}

+static inline void get_monotonic_boottime64(struct timespec64 *ts)
+{
+ *ts = ktime_to_timespec64(ktime_get_boottime());
+}
+
static inline void timekeeping_clocktai(struct timespec *ts)
{
*ts = ktime_to_timespec(ktime_get_clocktai());
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 37e50aadd471..ce8221ac5f39 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -266,7 +266,7 @@ lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
/*
* Divide a ktime value by a nanosecond value
*/
-u64 ktime_divns(const ktime_t kt, s64 div)
+u64 __ktime_divns(const ktime_t kt, s64 div)
{
u64 dclc;
int sft = 0;
@@ -282,7 +282,7 @@ u64 ktime_divns(const ktime_t kt, s64 div)

return dclc;
}
-EXPORT_SYMBOL_GPL(ktime_divns);
+EXPORT_SYMBOL_GPL(__ktime_divns);
#endif /* BITS_PER_LONG >= 64 */

/*
@@ -440,6 +440,37 @@ static inline void debug_deactivate(struct hrtimer *timer)
trace_hrtimer_cancel(timer);
}

+#if defined(CONFIG_NO_HZ_COMMON) || defined(CONFIG_HIGH_RES_TIMERS)
+static ktime_t __hrtimer_get_next_event(struct hrtimer_cpu_base *cpu_base)
+{
+ struct hrtimer_clock_base *base = cpu_base->clock_base;
+ ktime_t expires, expires_next = { .tv64 = KTIME_MAX };
+ int i;
+
+ for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
+ struct timerqueue_node *next;
+ struct hrtimer *timer;
+
+ next = timerqueue_getnext(&base->active);
+ if (!next)
+ continue;
+
+ timer = container_of(next, struct hrtimer, node);
+ expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
+ if (expires.tv64 < expires_next.tv64)
+ expires_next = expires;
+ }
+ /*
+ * clock_was_set() might have changed base->offset of any of
+ * the clock bases so the result might be negative. Fix it up
+ * to prevent a false positive in clockevents_program_event().
+ */
+ if (expires_next.tv64 < 0)
+ expires_next.tv64 = 0;
+ return expires_next;
+}
+#endif
+
/* High resolution timer related functions */
#ifdef CONFIG_HIGH_RES_TIMERS

@@ -488,32 +519,7 @@ static inline int hrtimer_hres_active(void)
static void
hrtimer_force_reprogram(struct hrtimer_cpu_base *cpu_base, int skip_equal)
{
- int i;
- struct hrtimer_clock_base *base = cpu_base->clock_base;
- ktime_t expires, expires_next;
-
- expires_next.tv64 = KTIME_MAX;
-
- for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
- struct hrtimer *timer;
- struct timerqueue_node *next;
-
- next = timerqueue_getnext(&base->active);
- if (!next)
- continue;
- timer = container_of(next, struct hrtimer, node);
-
- expires = ktime_sub(hrtimer_get_expires(timer), base->offset);
- /*
- * clock_was_set() has changed base->offset so the
- * result might be negative. Fix it up to prevent a
- * false positive in clockevents_program_event()
- */
- if (expires.tv64 < 0)
- expires.tv64 = 0;
- if (expires.tv64 < expires_next.tv64)
- expires_next = expires;
- }
+ ktime_t expires_next = __hrtimer_get_next_event(cpu_base);

if (skip_equal && expires_next.tv64 == cpu_base->expires_next.tv64)
return;
@@ -587,6 +593,15 @@ static int hrtimer_reprogram(struct hrtimer *timer,
return 0;

/*
+ * When the target cpu of the timer is currently executing
+ * hrtimer_interrupt(), then we do not touch the clock event
+ * device. hrtimer_interrupt() will reevaluate all clock bases
+ * before reprogramming the device.
+ */
+ if (cpu_base->in_hrtirq)
+ return 0;
+
+ /*
* If a hang was detected in the last timer interrupt then we
* do not schedule a timer which is earlier than the expiry
* which we enforced in the hang detection. We want the system
@@ -1104,29 +1119,14 @@ EXPORT_SYMBOL_GPL(hrtimer_get_remaining);
ktime_t hrtimer_get_next_event(void)
{
struct hrtimer_cpu_base *cpu_base = this_cpu_ptr(&hrtimer_bases);
- struct hrtimer_clock_base *base = cpu_base->clock_base;
- ktime_t delta, mindelta = { .tv64 = KTIME_MAX };
+ ktime_t mindelta = { .tv64 = KTIME_MAX };
unsigned long flags;
- int i;

raw_spin_lock_irqsave(&cpu_base->lock, flags);

- if (!hrtimer_hres_active()) {
- for (i = 0; i < HRTIMER_MAX_CLOCK_BASES; i++, base++) {
- struct hrtimer *timer;
- struct timerqueue_node *next;
-
- next = timerqueue_getnext(&base->active);
- if (!next)
- continue;
-
- timer = container_of(next, struct hrtimer, node);
- delta.tv64 = hrtimer_get_expires_tv64(timer);
- delta = ktime_sub(delta, base->get_time());
- if (delta.tv64 < mindelta.tv64)
- mindelta.tv64 = delta.tv64;
- }
- }
+ if (!hrtimer_hres_active())
+ mindelta = ktime_sub(__hrtimer_get_next_event(cpu_base),
+ ktime_get());

raw_spin_unlock_irqrestore(&cpu_base->lock, flags);

@@ -1253,7 +1253,7 @@ void hrtimer_interrupt(struct clock_event_device *dev)
raw_spin_lock(&cpu_base->lock);
entry_time = now = hrtimer_update_base(cpu_base);
retry:
- expires_next.tv64 = KTIME_MAX;
+ cpu_base->in_hrtirq = 1;
/*
* We set expires_next to KTIME_MAX here with cpu_base->lock
* held to prevent that a timer is enqueued in our queue via
@@ -1291,28 +1291,20 @@ void hrtimer_interrupt(struct clock_event_device *dev)
* are right-of a not yet expired timer, because that
* timer will have to trigger a wakeup anyway.
*/
-
- if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer)) {
- ktime_t expires;
-
- expires = ktime_sub(hrtimer_get_expires(timer),
- base->offset);
- if (expires.tv64 < 0)
- expires.tv64 = KTIME_MAX;
- if (expires.tv64 < expires_next.tv64)
- expires_next = expires;
+ if (basenow.tv64 < hrtimer_get_softexpires_tv64(timer))
break;
- }

__run_hrtimer(timer, &basenow);
}
}
-
+ /* Reevaluate the clock bases for the next expiry */
+ expires_next = __hrtimer_get_next_event(cpu_base);
/*
* Store the new expiry value so the migration code can verify
* against it.
*/
cpu_base->expires_next = expires_next;
+ cpu_base->in_hrtirq = 0;
raw_spin_unlock(&cpu_base->lock);

/* Reprogramming necessary ? */
diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c
index 87a346fd6d61..183dfe2191c6 100644
--- a/kernel/time/ntp.c
+++ b/kernel/time/ntp.c
@@ -488,13 +488,13 @@ static void sync_cmos_clock(struct work_struct *work)

getnstimeofday64(&now);
if (abs(now.tv_nsec - (NSEC_PER_SEC / 2)) <= tick_nsec * 5) {
- struct timespec adjust = timespec64_to_timespec(now);
+ struct timespec64 adjust = now;

fail = -ENODEV;
if (persistent_clock_is_local)
adjust.tv_sec -= (sys_tz.tz_minuteswest * 60);
#ifdef CONFIG_GENERIC_CMOS_UPDATE
- fail = update_persistent_clock(adjust);
+ fail = update_persistent_clock(timespec64_to_timespec(adjust));
#endif
#ifdef CONFIG_RTC_SYSTOHC
if (fail == -ENODEV)
diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c
index 6a931852082f..b124af259800 100644
--- a/kernel/time/timekeeping.c
+++ b/kernel/time/timekeeping.c
@@ -1659,24 +1659,24 @@ void update_wall_time(void)
}

/**
- * getboottime - Return the real time of system boot.
- * @ts: pointer to the timespec to be set
+ * getboottime64 - Return the real time of system boot.
+ * @ts: pointer to the timespec64 to be set
*
- * Returns the wall-time of boot in a timespec.
+ * Returns the wall-time of boot in a timespec64.
*
* This is based on the wall_to_monotonic offset and the total suspend
* time. Calls to settimeofday will affect the value returned (which
* basically means that however wrong your real time clock is at boot time,
* you get the right time here).
*/
-void getboottime(struct timespec *ts)
+void getboottime64(struct timespec64 *ts)
{
struct timekeeper *tk = &tk_core.timekeeper;
ktime_t t = ktime_sub(tk->offs_real, tk->offs_boot);

- *ts = ktime_to_timespec(t);
+ *ts = ktime_to_timespec64(t);
}
-EXPORT_SYMBOL_GPL(getboottime);
+EXPORT_SYMBOL_GPL(getboottime64);

unsigned long get_seconds(void)
{
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