]> Pileus Git - ~andy/linux/blobdiff - kernel/time/timekeeping.c
time: Avoid making adjustments if we haven't accumulated anything
[~andy/linux] / kernel / time / timekeeping.c
index f045cc50832d0fc8aee045755d3ba60d655f2647..0c1485e42be6eec17d2525cbb4f2383daf8e2274 100644 (file)
@@ -65,14 +65,14 @@ struct timekeeper {
         * used instead.
         */
        struct timespec         wall_to_monotonic;
-       /* time spent in suspend */
-       struct timespec         total_sleep_time;
-       /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
-       struct timespec         raw_time;
        /* Offset clock monotonic -> clock realtime */
        ktime_t                 offs_real;
+       /* time spent in suspend */
+       struct timespec         total_sleep_time;
        /* Offset clock monotonic -> clock boottime */
        ktime_t                 offs_boot;
+       /* The raw monotonic time for the CLOCK_MONOTONIC_RAW posix clock. */
+       struct timespec         raw_time;
        /* Seqlock for all timekeeper values */
        seqlock_t               lock;
 };
@@ -108,13 +108,39 @@ static struct timespec tk_xtime(struct timekeeper *tk)
 static void tk_set_xtime(struct timekeeper *tk, const struct timespec *ts)
 {
        tk->xtime_sec = ts->tv_sec;
-       tk->xtime_nsec = ts->tv_nsec << tk->shift;
+       tk->xtime_nsec = (u64)ts->tv_nsec << tk->shift;
 }
 
 static void tk_xtime_add(struct timekeeper *tk, const struct timespec *ts)
 {
        tk->xtime_sec += ts->tv_sec;
-       tk->xtime_nsec += ts->tv_nsec << tk->shift;
+       tk->xtime_nsec += (u64)ts->tv_nsec << tk->shift;
+       tk_normalize_xtime(tk);
+}
+
+static void tk_set_wall_to_mono(struct timekeeper *tk, struct timespec wtm)
+{
+       struct timespec tmp;
+
+       /*
+        * Verify consistency of: offset_real = -wall_to_monotonic
+        * before modifying anything
+        */
+       set_normalized_timespec(&tmp, -tk->wall_to_monotonic.tv_sec,
+                                       -tk->wall_to_monotonic.tv_nsec);
+       WARN_ON_ONCE(tk->offs_real.tv64 != timespec_to_ktime(tmp).tv64);
+       tk->wall_to_monotonic = wtm;
+       set_normalized_timespec(&tmp, -wtm.tv_sec, -wtm.tv_nsec);
+       tk->offs_real = timespec_to_ktime(tmp);
+}
+
+static void tk_set_sleep_time(struct timekeeper *tk, struct timespec t)
+{
+       /* Verify consistency before modifying */
+       WARN_ON_ONCE(tk->offs_boot.tv64 != timespec_to_ktime(tk->total_sleep_time).tv64);
+
+       tk->total_sleep_time    = t;
+       tk->offs_boot           = timespec_to_ktime(t);
 }
 
 /**
@@ -217,14 +243,6 @@ static inline s64 timekeeping_get_ns_raw(struct timekeeper *tk)
        return nsec + arch_gettimeoffset();
 }
 
-static void update_rt_offset(struct timekeeper *tk)
-{
-       struct timespec tmp, *wtm = &tk->wall_to_monotonic;
-
-       set_normalized_timespec(&tmp, -wtm->tv_sec, -wtm->tv_nsec);
-       tk->offs_real = timespec_to_ktime(tmp);
-}
-
 /* must hold write on timekeeper.lock */
 static void timekeeping_update(struct timekeeper *tk, bool clearntp)
 {
@@ -234,12 +252,10 @@ static void timekeeping_update(struct timekeeper *tk, bool clearntp)
                tk->ntp_error = 0;
                ntp_clear();
        }
-       update_rt_offset(tk);
        xt = tk_xtime(tk);
        update_vsyscall(&xt, &tk->wall_to_monotonic, tk->clock, tk->mult);
 }
 
-
 /**
  * timekeeping_forward_now - update clock to the current time
  *
@@ -261,7 +277,7 @@ static void timekeeping_forward_now(struct timekeeper *tk)
        tk->xtime_nsec += cycle_delta * tk->mult;
 
        /* If arch requires, add in gettimeoffset() */
-       tk->xtime_nsec += arch_gettimeoffset() << tk->shift;
+       tk->xtime_nsec += (u64)arch_gettimeoffset() << tk->shift;
 
        tk_normalize_xtime(tk);
 
@@ -277,18 +293,19 @@ static void timekeeping_forward_now(struct timekeeper *tk)
  */
 void getnstimeofday(struct timespec *ts)
 {
+       struct timekeeper *tk = &timekeeper;
        unsigned long seq;
        s64 nsecs = 0;
 
        WARN_ON(timekeeping_suspended);
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
+               seq = read_seqbegin(&tk->lock);
 
-               ts->tv_sec = timekeeper.xtime_sec;
-               ts->tv_nsec = timekeeping_get_ns(&timekeeper);
+               ts->tv_sec = tk->xtime_sec;
+               ts->tv_nsec = timekeeping_get_ns(tk);
 
-       } while (read_seqretry(&timekeeper.lock, seq));
+       } while (read_seqretry(&tk->lock, seq));
 
        timespec_add_ns(ts, nsecs);
 }
@@ -296,19 +313,18 @@ EXPORT_SYMBOL(getnstimeofday);
 
 ktime_t ktime_get(void)
 {
+       struct timekeeper *tk = &timekeeper;
        unsigned int seq;
        s64 secs, nsecs;
 
        WARN_ON(timekeeping_suspended);
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
-               secs = timekeeper.xtime_sec +
-                               timekeeper.wall_to_monotonic.tv_sec;
-               nsecs = timekeeping_get_ns(&timekeeper) +
-                               timekeeper.wall_to_monotonic.tv_nsec;
+               seq = read_seqbegin(&tk->lock);
+               secs = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
+               nsecs = timekeeping_get_ns(tk) + tk->wall_to_monotonic.tv_nsec;
 
-       } while (read_seqretry(&timekeeper.lock, seq));
+       } while (read_seqretry(&tk->lock, seq));
        /*
         * Use ktime_set/ktime_add_ns to create a proper ktime on
         * 32-bit architectures without CONFIG_KTIME_SCALAR.
@@ -327,18 +343,19 @@ EXPORT_SYMBOL_GPL(ktime_get);
  */
 void ktime_get_ts(struct timespec *ts)
 {
+       struct timekeeper *tk = &timekeeper;
        struct timespec tomono;
        unsigned int seq;
 
        WARN_ON(timekeeping_suspended);
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
-               ts->tv_sec = timekeeper.xtime_sec;
-               ts->tv_nsec = timekeeping_get_ns(&timekeeper);
-               tomono = timekeeper.wall_to_monotonic;
+               seq = read_seqbegin(&tk->lock);
+               ts->tv_sec = tk->xtime_sec;
+               ts->tv_nsec = timekeeping_get_ns(tk);
+               tomono = tk->wall_to_monotonic;
 
-       } while (read_seqretry(&timekeeper.lock, seq));
+       } while (read_seqretry(&tk->lock, seq));
 
        set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec,
                                ts->tv_nsec + tomono.tv_nsec);
@@ -358,22 +375,23 @@ EXPORT_SYMBOL_GPL(ktime_get_ts);
  */
 void getnstime_raw_and_real(struct timespec *ts_raw, struct timespec *ts_real)
 {
+       struct timekeeper *tk = &timekeeper;
        unsigned long seq;
        s64 nsecs_raw, nsecs_real;
 
        WARN_ON_ONCE(timekeeping_suspended);
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
+               seq = read_seqbegin(&tk->lock);
 
-               *ts_raw = timekeeper.raw_time;
-               ts_real->tv_sec = timekeeper.xtime_sec;
+               *ts_raw = tk->raw_time;
+               ts_real->tv_sec = tk->xtime_sec;
                ts_real->tv_nsec = 0;
 
-               nsecs_raw = timekeeping_get_ns_raw(&timekeeper);
-               nsecs_real = timekeeping_get_ns(&timekeeper);
+               nsecs_raw = timekeeping_get_ns_raw(tk);
+               nsecs_real = timekeeping_get_ns(tk);
 
-       } while (read_seqretry(&timekeeper.lock, seq));
+       } while (read_seqretry(&tk->lock, seq));
 
        timespec_add_ns(ts_raw, nsecs_raw);
        timespec_add_ns(ts_real, nsecs_real);
@@ -406,28 +424,28 @@ EXPORT_SYMBOL(do_gettimeofday);
  */
 int do_settimeofday(const struct timespec *tv)
 {
+       struct timekeeper *tk = &timekeeper;
        struct timespec ts_delta, xt;
        unsigned long flags;
 
-       if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
+       if (!timespec_valid(tv))
                return -EINVAL;
 
-       write_seqlock_irqsave(&timekeeper.lock, flags);
+       write_seqlock_irqsave(&tk->lock, flags);
 
-       timekeeping_forward_now(&timekeeper);
+       timekeeping_forward_now(tk);
 
-       xt = tk_xtime(&timekeeper);
+       xt = tk_xtime(tk);
        ts_delta.tv_sec = tv->tv_sec - xt.tv_sec;
        ts_delta.tv_nsec = tv->tv_nsec - xt.tv_nsec;
 
-       timekeeper.wall_to_monotonic =
-                       timespec_sub(timekeeper.wall_to_monotonic, ts_delta);
+       tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, ts_delta));
 
-       tk_set_xtime(&timekeeper, tv);
+       tk_set_xtime(tk, tv);
 
-       timekeeping_update(&timekeeper, true);
+       timekeeping_update(tk, true);
 
-       write_sequnlock_irqrestore(&timekeeper.lock, flags);
+       write_sequnlock_irqrestore(&tk->lock, flags);
 
        /* signal hrtimers about time change */
        clock_was_set();
@@ -436,7 +454,6 @@ int do_settimeofday(const struct timespec *tv)
 }
 EXPORT_SYMBOL(do_settimeofday);
 
-
 /**
  * timekeeping_inject_offset - Adds or subtracts from the current time.
  * @tv:                pointer to the timespec variable containing the offset
@@ -445,28 +462,37 @@ EXPORT_SYMBOL(do_settimeofday);
  */
 int timekeeping_inject_offset(struct timespec *ts)
 {
+       struct timekeeper *tk = &timekeeper;
        unsigned long flags;
+       struct timespec tmp;
+       int ret = 0;
 
        if ((unsigned long)ts->tv_nsec >= NSEC_PER_SEC)
                return -EINVAL;
 
-       write_seqlock_irqsave(&timekeeper.lock, flags);
+       write_seqlock_irqsave(&tk->lock, flags);
 
-       timekeeping_forward_now(&timekeeper);
+       timekeeping_forward_now(tk);
 
+       /* Make sure the proposed value is valid */
+       tmp = timespec_add(tk_xtime(tk),  *ts);
+       if (!timespec_valid(&tmp)) {
+               ret = -EINVAL;
+               goto error;
+       }
 
-       tk_xtime_add(&timekeeper, ts);
-       timekeeper.wall_to_monotonic =
-                               timespec_sub(timekeeper.wall_to_monotonic, *ts);
+       tk_xtime_add(tk, ts);
+       tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *ts));
 
-       timekeeping_update(&timekeeper, true);
+error: /* even if we error out, we forwarded the time, so call update */
+       timekeeping_update(tk, true);
 
-       write_sequnlock_irqrestore(&timekeeper.lock, flags);
+       write_sequnlock_irqrestore(&tk->lock, flags);
 
        /* signal hrtimers about time change */
        clock_was_set();
 
-       return 0;
+       return ret;
 }
 EXPORT_SYMBOL(timekeeping_inject_offset);
 
@@ -477,23 +503,24 @@ EXPORT_SYMBOL(timekeeping_inject_offset);
  */
 static int change_clocksource(void *data)
 {
+       struct timekeeper *tk = &timekeeper;
        struct clocksource *new, *old;
        unsigned long flags;
 
        new = (struct clocksource *) data;
 
-       write_seqlock_irqsave(&timekeeper.lock, flags);
+       write_seqlock_irqsave(&tk->lock, flags);
 
-       timekeeping_forward_now(&timekeeper);
+       timekeeping_forward_now(tk);
        if (!new->enable || new->enable(new) == 0) {
-               old = timekeeper.clock;
-               tk_setup_internals(&timekeeper, new);
+               old = tk->clock;
+               tk_setup_internals(tk, new);
                if (old->disable)
                        old->disable(old);
        }
-       timekeeping_update(&timekeeper, true);
+       timekeeping_update(tk, true);
 
-       write_sequnlock_irqrestore(&timekeeper.lock, flags);
+       write_sequnlock_irqrestore(&tk->lock, flags);
 
        return 0;
 }
@@ -507,7 +534,9 @@ static int change_clocksource(void *data)
  */
 void timekeeping_notify(struct clocksource *clock)
 {
-       if (timekeeper.clock == clock)
+       struct timekeeper *tk = &timekeeper;
+
+       if (tk->clock == clock)
                return;
        stop_machine(change_clocksource, clock, NULL);
        tick_clock_notify();
@@ -536,35 +565,36 @@ EXPORT_SYMBOL_GPL(ktime_get_real);
  */
 void getrawmonotonic(struct timespec *ts)
 {
+       struct timekeeper *tk = &timekeeper;
        unsigned long seq;
        s64 nsecs;
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
-               nsecs = timekeeping_get_ns_raw(&timekeeper);
-               *ts = timekeeper.raw_time;
+               seq = read_seqbegin(&tk->lock);
+               nsecs = timekeeping_get_ns_raw(tk);
+               *ts = tk->raw_time;
 
-       } while (read_seqretry(&timekeeper.lock, seq));
+       } while (read_seqretry(&tk->lock, seq));
 
        timespec_add_ns(ts, nsecs);
 }
 EXPORT_SYMBOL(getrawmonotonic);
 
-
 /**
  * timekeeping_valid_for_hres - Check if timekeeping is suitable for hres
  */
 int timekeeping_valid_for_hres(void)
 {
+       struct timekeeper *tk = &timekeeper;
        unsigned long seq;
        int ret;
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
+               seq = read_seqbegin(&tk->lock);
 
-               ret = timekeeper.clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
+               ret = tk->clock->flags & CLOCK_SOURCE_VALID_FOR_HRES;
 
-       } while (read_seqretry(&timekeeper.lock, seq));
+       } while (read_seqretry(&tk->lock, seq));
 
        return ret;
 }
@@ -574,15 +604,16 @@ int timekeeping_valid_for_hres(void)
  */
 u64 timekeeping_max_deferment(void)
 {
+       struct timekeeper *tk = &timekeeper;
        unsigned long seq;
        u64 ret;
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
+               seq = read_seqbegin(&tk->lock);
 
-               ret = timekeeper.clock->max_idle_ns;
+               ret = tk->clock->max_idle_ns;
 
-       } while (read_seqretry(&timekeeper.lock, seq));
+       } while (read_seqretry(&tk->lock, seq));
 
        return ret;
 }
@@ -622,46 +653,56 @@ void __attribute__((weak)) read_boot_clock(struct timespec *ts)
  */
 void __init timekeeping_init(void)
 {
+       struct timekeeper *tk = &timekeeper;
        struct clocksource *clock;
        unsigned long flags;
-       struct timespec now, boot;
+       struct timespec now, boot, tmp;
 
        read_persistent_clock(&now);
+       if (!timespec_valid(&now)) {
+               pr_warn("WARNING: Persistent clock returned invalid value!\n"
+                       "         Check your CMOS/BIOS settings.\n");
+               now.tv_sec = 0;
+               now.tv_nsec = 0;
+       }
+
        read_boot_clock(&boot);
+       if (!timespec_valid(&boot)) {
+               pr_warn("WARNING: Boot clock returned invalid value!\n"
+                       "         Check your CMOS/BIOS settings.\n");
+               boot.tv_sec = 0;
+               boot.tv_nsec = 0;
+       }
 
-       seqlock_init(&timekeeper.lock);
+       seqlock_init(&tk->lock);
 
        ntp_init();
 
-       write_seqlock_irqsave(&timekeeper.lock, flags);
+       write_seqlock_irqsave(&tk->lock, flags);
        clock = clocksource_default_clock();
        if (clock->enable)
                clock->enable(clock);
-       tk_setup_internals(&timekeeper, clock);
+       tk_setup_internals(tk, clock);
 
-       tk_set_xtime(&timekeeper, &now);
-       timekeeper.raw_time.tv_sec = 0;
-       timekeeper.raw_time.tv_nsec = 0;
+       tk_set_xtime(tk, &now);
+       tk->raw_time.tv_sec = 0;
+       tk->raw_time.tv_nsec = 0;
        if (boot.tv_sec == 0 && boot.tv_nsec == 0)
-               boot = tk_xtime(&timekeeper);
-
-       set_normalized_timespec(&timekeeper.wall_to_monotonic,
-                               -boot.tv_sec, -boot.tv_nsec);
-       update_rt_offset(&timekeeper);
-       timekeeper.total_sleep_time.tv_sec = 0;
-       timekeeper.total_sleep_time.tv_nsec = 0;
-       write_sequnlock_irqrestore(&timekeeper.lock, flags);
+               boot = tk_xtime(tk);
+
+       set_normalized_timespec(&tmp, -boot.tv_sec, -boot.tv_nsec);
+       tk_set_wall_to_mono(tk, tmp);
+
+       tmp.tv_sec = 0;
+       tmp.tv_nsec = 0;
+       tk_set_sleep_time(tk, tmp);
+
+       write_sequnlock_irqrestore(&tk->lock, flags);
 }
 
 /* time in seconds when suspend began */
 static struct timespec timekeeping_suspend_time;
 
-static void update_sleep_time(struct timespec t)
-{
-       timekeeper.total_sleep_time = t;
-       timekeeper.offs_boot = timespec_to_ktime(t);
-}
-
 /**
  * __timekeeping_inject_sleeptime - Internal function to add sleep interval
  * @delta: pointer to a timespec delta value
@@ -677,13 +718,11 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
                                        "sleep delta value!\n");
                return;
        }
-
        tk_xtime_add(tk, delta);
-       tk->wall_to_monotonic = timespec_sub(tk->wall_to_monotonic, *delta);
-       update_sleep_time(timespec_add(tk->total_sleep_time, *delta));
+       tk_set_wall_to_mono(tk, timespec_sub(tk->wall_to_monotonic, *delta));
+       tk_set_sleep_time(tk, timespec_add(tk->total_sleep_time, *delta));
 }
 
-
 /**
  * timekeeping_inject_sleeptime - Adds suspend interval to timeekeeping values
  * @delta: pointer to a timespec delta value
@@ -696,6 +735,7 @@ static void __timekeeping_inject_sleeptime(struct timekeeper *tk,
  */
 void timekeeping_inject_sleeptime(struct timespec *delta)
 {
+       struct timekeeper *tk = &timekeeper;
        unsigned long flags;
        struct timespec ts;
 
@@ -704,21 +744,20 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
        if (!(ts.tv_sec == 0 && ts.tv_nsec == 0))
                return;
 
-       write_seqlock_irqsave(&timekeeper.lock, flags);
+       write_seqlock_irqsave(&tk->lock, flags);
 
-       timekeeping_forward_now(&timekeeper);
+       timekeeping_forward_now(tk);
 
-       __timekeeping_inject_sleeptime(&timekeeper, delta);
+       __timekeeping_inject_sleeptime(tk, delta);
 
-       timekeeping_update(&timekeeper, true);
+       timekeeping_update(tk, true);
 
-       write_sequnlock_irqrestore(&timekeeper.lock, flags);
+       write_sequnlock_irqrestore(&tk->lock, flags);
 
        /* signal hrtimers about time change */
        clock_was_set();
 }
 
-
 /**
  * timekeeping_resume - Resumes the generic timekeeping subsystem.
  *
@@ -728,6 +767,7 @@ void timekeeping_inject_sleeptime(struct timespec *delta)
  */
 static void timekeeping_resume(void)
 {
+       struct timekeeper *tk = &timekeeper;
        unsigned long flags;
        struct timespec ts;
 
@@ -735,18 +775,18 @@ static void timekeeping_resume(void)
 
        clocksource_resume();
 
-       write_seqlock_irqsave(&timekeeper.lock, flags);
+       write_seqlock_irqsave(&tk->lock, flags);
 
        if (timespec_compare(&ts, &timekeeping_suspend_time) > 0) {
                ts = timespec_sub(ts, timekeeping_suspend_time);
-               __timekeeping_inject_sleeptime(&timekeeper, &ts);
+               __timekeeping_inject_sleeptime(tk, &ts);
        }
        /* re-base the last cycle value */
-       timekeeper.clock->cycle_last = timekeeper.clock->read(timekeeper.clock);
-       timekeeper.ntp_error = 0;
+       tk->clock->cycle_last = tk->clock->read(tk->clock);
+       tk->ntp_error = 0;
        timekeeping_suspended = 0;
-       timekeeping_update(&timekeeper, false);
-       write_sequnlock_irqrestore(&timekeeper.lock, flags);
+       timekeeping_update(tk, false);
+       write_sequnlock_irqrestore(&tk->lock, flags);
 
        touch_softlockup_watchdog();
 
@@ -758,14 +798,15 @@ static void timekeeping_resume(void)
 
 static int timekeeping_suspend(void)
 {
+       struct timekeeper *tk = &timekeeper;
        unsigned long flags;
        struct timespec         delta, delta_delta;
        static struct timespec  old_delta;
 
        read_persistent_clock(&timekeeping_suspend_time);
 
-       write_seqlock_irqsave(&timekeeper.lock, flags);
-       timekeeping_forward_now(&timekeeper);
+       write_seqlock_irqsave(&tk->lock, flags);
+       timekeeping_forward_now(tk);
        timekeeping_suspended = 1;
 
        /*
@@ -774,7 +815,7 @@ static int timekeeping_suspend(void)
         * try to compensate so the difference in system time
         * and persistent_clock time stays close to constant.
         */
-       delta = timespec_sub(tk_xtime(&timekeeper), timekeeping_suspend_time);
+       delta = timespec_sub(tk_xtime(tk), timekeeping_suspend_time);
        delta_delta = timespec_sub(delta, old_delta);
        if (abs(delta_delta.tv_sec)  >= 2) {
                /*
@@ -787,7 +828,7 @@ static int timekeeping_suspend(void)
                timekeeping_suspend_time =
                        timespec_add(timekeeping_suspend_time, delta_delta);
        }
-       write_sequnlock_irqrestore(&timekeeper.lock, flags);
+       write_sequnlock_irqrestore(&tk->lock, flags);
 
        clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
        clocksource_suspend();
@@ -898,27 +939,29 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
                 * the error. This causes the likely below to be unlikely.
                 *
                 * The proper fix is to avoid rounding up by using
-                * the high precision timekeeper.xtime_nsec instead of
+                * the high precision tk->xtime_nsec instead of
                 * xtime.tv_nsec everywhere. Fixing this will take some
                 * time.
                 */
                if (likely(error <= interval))
                        adj = 1;
                else
-                       adj = timekeeping_bigadjust(tk, error, &interval,
-                                                       &offset);
-       } else if (error < -interval) {
-               /* See comment above, this is just switched for the negative */
-               error >>= 2;
-               if (likely(error >= -interval)) {
-                       adj = -1;
-                       interval = -interval;
-                       offset = -offset;
-               } else
-                       adj = timekeeping_bigadjust(tk, error, &interval,
-                                                       &offset);
-       } else
-               return;
+                       adj = timekeeping_bigadjust(tk, error, &interval, &offset);
+       } else {
+               if (error < -interval) {
+                       /* See comment above, this is just switched for the negative */
+                       error >>= 2;
+                       if (likely(error >= -interval)) {
+                               adj = -1;
+                               interval = -interval;
+                               offset = -offset;
+                       } else {
+                               adj = timekeeping_bigadjust(tk, error, &interval, &offset);
+                       }
+               } else {
+                       goto out_adjust;
+               }
+       }
 
        if (unlikely(tk->clock->maxadj &&
                (tk->mult + adj > tk->clock->mult + tk->clock->maxadj))) {
@@ -981,6 +1024,7 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
        tk->xtime_nsec -= offset;
        tk->ntp_error -= (interval - offset) << tk->ntp_error_shift;
 
+out_adjust:
        /*
         * It may be possible that when we entered this function, xtime_nsec
         * was very small.  Further, if we're slightly speeding the clocksource
@@ -1003,7 +1047,6 @@ static void timekeeping_adjust(struct timekeeper *tk, s64 offset)
 
 }
 
-
 /**
  * accumulate_nsecs_to_secs - Accumulates nsecs into secs
  *
@@ -1024,15 +1067,21 @@ static inline void accumulate_nsecs_to_secs(struct timekeeper *tk)
 
                /* Figure out if its a leap sec and apply if needed */
                leap = second_overflow(tk->xtime_sec);
-               tk->xtime_sec += leap;
-               tk->wall_to_monotonic.tv_sec -= leap;
-               if (leap)
-                       clock_was_set_delayed();
+               if (unlikely(leap)) {
+                       struct timespec ts;
+
+                       tk->xtime_sec += leap;
+
+                       ts.tv_sec = leap;
+                       ts.tv_nsec = 0;
+                       tk_set_wall_to_mono(tk,
+                               timespec_sub(tk->wall_to_monotonic, ts));
 
+                       clock_was_set_delayed();
+               }
        }
 }
 
-
 /**
  * logarithmic_accumulation - shifted accumulation of cycles
  *
@@ -1076,7 +1125,6 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
        return offset;
 }
 
-
 /**
  * update_wall_time - Uses the current clocksource to increment the wall time
  *
@@ -1084,25 +1132,30 @@ static cycle_t logarithmic_accumulation(struct timekeeper *tk, cycle_t offset,
 static void update_wall_time(void)
 {
        struct clocksource *clock;
+       struct timekeeper *tk = &timekeeper;
        cycle_t offset;
        int shift = 0, maxshift;
        unsigned long flags;
        s64 remainder;
 
-       write_seqlock_irqsave(&timekeeper.lock, flags);
+       write_seqlock_irqsave(&tk->lock, flags);
 
        /* Make sure we're fully resumed: */
        if (unlikely(timekeeping_suspended))
                goto out;
 
-       clock = timekeeper.clock;
+       clock = tk->clock;
 
 #ifdef CONFIG_ARCH_USES_GETTIMEOFFSET
-       offset = timekeeper.cycle_interval;
+       offset = tk->cycle_interval;
 #else
        offset = (clock->read(clock) - clock->cycle_last) & clock->mask;
 #endif
 
+       /* Check if there's really nothing to do */
+       if (offset < tk->cycle_interval)
+               goto out;
+
        /*
         * With NO_HZ we may have to accumulate many cycle_intervals
         * (think "ticks") worth of time at once. To do this efficiently,
@@ -1111,19 +1164,19 @@ static void update_wall_time(void)
         * chunk in one go, and then try to consume the next smaller
         * doubled multiple.
         */
-       shift = ilog2(offset) - ilog2(timekeeper.cycle_interval);
+       shift = ilog2(offset) - ilog2(tk->cycle_interval);
        shift = max(0, shift);
        /* Bound shift to one less than what overflows tick_length */
        maxshift = (64 - (ilog2(ntp_tick_length())+1)) - 1;
        shift = min(shift, maxshift);
-       while (offset >= timekeeper.cycle_interval) {
-               offset = logarithmic_accumulation(&timekeeper, offset, shift);
-               if(offset < timekeeper.cycle_interval<<shift)
+       while (offset >= tk->cycle_interval) {
+               offset = logarithmic_accumulation(tk, offset, shift);
+               if (offset < tk->cycle_interval<<shift)
                        shift--;
        }
 
        /* correct the clock when NTP error is too big */
-       timekeeping_adjust(&timekeeper, offset);
+       timekeeping_adjust(tk, offset);
 
 
        /*
@@ -1135,21 +1188,21 @@ static void update_wall_time(void)
        * the vsyscall implementations are converted to use xtime_nsec
        * (shifted nanoseconds), this can be killed.
        */
-       remainder = timekeeper.xtime_nsec & ((1 << timekeeper.shift) - 1);
-       timekeeper.xtime_nsec -= remainder;
-       timekeeper.xtime_nsec += 1 << timekeeper.shift;
-       timekeeper.ntp_error += remainder << timekeeper.ntp_error_shift;
+       remainder = tk->xtime_nsec & ((1ULL << tk->shift) - 1);
+       tk->xtime_nsec -= remainder;
+       tk->xtime_nsec += 1ULL << tk->shift;
+       tk->ntp_error += remainder << tk->ntp_error_shift;
 
        /*
         * Finally, make sure that after the rounding
         * xtime_nsec isn't larger than NSEC_PER_SEC
         */
-       accumulate_nsecs_to_secs(&timekeeper);
+       accumulate_nsecs_to_secs(tk);
 
-       timekeeping_update(&timekeeper, false);
+       timekeeping_update(tk, false);
 
 out:
-       write_sequnlock_irqrestore(&timekeeper.lock, flags);
+       write_sequnlock_irqrestore(&tk->lock, flags);
 
 }
 
@@ -1166,18 +1219,18 @@ out:
  */
 void getboottime(struct timespec *ts)
 {
+       struct timekeeper *tk = &timekeeper;
        struct timespec boottime = {
-               .tv_sec = timekeeper.wall_to_monotonic.tv_sec +
-                               timekeeper.total_sleep_time.tv_sec,
-               .tv_nsec = timekeeper.wall_to_monotonic.tv_nsec +
-                               timekeeper.total_sleep_time.tv_nsec
+               .tv_sec = tk->wall_to_monotonic.tv_sec +
+                               tk->total_sleep_time.tv_sec,
+               .tv_nsec = tk->wall_to_monotonic.tv_nsec +
+                               tk->total_sleep_time.tv_nsec
        };
 
        set_normalized_timespec(ts, -boottime.tv_sec, -boottime.tv_nsec);
 }
 EXPORT_SYMBOL_GPL(getboottime);
 
-
 /**
  * get_monotonic_boottime - Returns monotonic time since boot
  * @ts:                pointer to the timespec to be set
@@ -1189,19 +1242,20 @@ EXPORT_SYMBOL_GPL(getboottime);
  */
 void get_monotonic_boottime(struct timespec *ts)
 {
+       struct timekeeper *tk = &timekeeper;
        struct timespec tomono, sleep;
        unsigned int seq;
 
        WARN_ON(timekeeping_suspended);
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
-               ts->tv_sec = timekeeper.xtime_sec;
-               ts->tv_nsec = timekeeping_get_ns(&timekeeper);
-               tomono = timekeeper.wall_to_monotonic;
-               sleep = timekeeper.total_sleep_time;
+               seq = read_seqbegin(&tk->lock);
+               ts->tv_sec = tk->xtime_sec;
+               ts->tv_nsec = timekeeping_get_ns(tk);
+               tomono = tk->wall_to_monotonic;
+               sleep = tk->total_sleep_time;
 
-       } while (read_seqretry(&timekeeper.lock, seq));
+       } while (read_seqretry(&tk->lock, seq));
 
        set_normalized_timespec(ts, ts->tv_sec + tomono.tv_sec + sleep.tv_sec,
                        ts->tv_nsec + tomono.tv_nsec + sleep.tv_nsec);
@@ -1231,31 +1285,38 @@ EXPORT_SYMBOL_GPL(ktime_get_boottime);
  */
 void monotonic_to_bootbased(struct timespec *ts)
 {
-       *ts = timespec_add(*ts, timekeeper.total_sleep_time);
+       struct timekeeper *tk = &timekeeper;
+
+       *ts = timespec_add(*ts, tk->total_sleep_time);
 }
 EXPORT_SYMBOL_GPL(monotonic_to_bootbased);
 
 unsigned long get_seconds(void)
 {
-       return timekeeper.xtime_sec;
+       struct timekeeper *tk = &timekeeper;
+
+       return tk->xtime_sec;
 }
 EXPORT_SYMBOL(get_seconds);
 
 struct timespec __current_kernel_time(void)
 {
-       return tk_xtime(&timekeeper);
+       struct timekeeper *tk = &timekeeper;
+
+       return tk_xtime(tk);
 }
 
 struct timespec current_kernel_time(void)
 {
+       struct timekeeper *tk = &timekeeper;
        struct timespec now;
        unsigned long seq;
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
+               seq = read_seqbegin(&tk->lock);
 
-               now = tk_xtime(&timekeeper);
-       } while (read_seqretry(&timekeeper.lock, seq));
+               now = tk_xtime(tk);
+       } while (read_seqretry(&tk->lock, seq));
 
        return now;
 }
@@ -1263,15 +1324,16 @@ EXPORT_SYMBOL(current_kernel_time);
 
 struct timespec get_monotonic_coarse(void)
 {
+       struct timekeeper *tk = &timekeeper;
        struct timespec now, mono;
        unsigned long seq;
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
+               seq = read_seqbegin(&tk->lock);
 
-               now = tk_xtime(&timekeeper);
-               mono = timekeeper.wall_to_monotonic;
-       } while (read_seqretry(&timekeeper.lock, seq));
+               now = tk_xtime(tk);
+               mono = tk->wall_to_monotonic;
+       } while (read_seqretry(&tk->lock, seq));
 
        set_normalized_timespec(&now, now.tv_sec + mono.tv_sec,
                                now.tv_nsec + mono.tv_nsec);
@@ -1300,14 +1362,15 @@ void do_timer(unsigned long ticks)
 void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
                                struct timespec *wtom, struct timespec *sleep)
 {
+       struct timekeeper *tk = &timekeeper;
        unsigned long seq;
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
-               *xtim = tk_xtime(&timekeeper);
-               *wtom = timekeeper.wall_to_monotonic;
-               *sleep = timekeeper.total_sleep_time;
-       } while (read_seqretry(&timekeeper.lock, seq));
+               seq = read_seqbegin(&tk->lock);
+               *xtim = tk_xtime(tk);
+               *wtom = tk->wall_to_monotonic;
+               *sleep = tk->total_sleep_time;
+       } while (read_seqretry(&tk->lock, seq));
 }
 
 #ifdef CONFIG_HIGH_RES_TIMERS
@@ -1321,19 +1384,20 @@ void get_xtime_and_monotonic_and_sleep_offset(struct timespec *xtim,
  */
 ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
 {
+       struct timekeeper *tk = &timekeeper;
        ktime_t now;
        unsigned int seq;
        u64 secs, nsecs;
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
+               seq = read_seqbegin(&tk->lock);
 
-               secs = timekeeper.xtime_sec;
-               nsecs = timekeeping_get_ns(&timekeeper);
+               secs = tk->xtime_sec;
+               nsecs = timekeeping_get_ns(tk);
 
-               *offs_real = timekeeper.offs_real;
-               *offs_boot = timekeeper.offs_boot;
-       } while (read_seqretry(&timekeeper.lock, seq));
+               *offs_real = tk->offs_real;
+               *offs_boot = tk->offs_boot;
+       } while (read_seqretry(&tk->lock, seq));
 
        now = ktime_add_ns(ktime_set(secs, 0), nsecs);
        now = ktime_sub(now, *offs_real);
@@ -1346,19 +1410,19 @@ ktime_t ktime_get_update_offsets(ktime_t *offs_real, ktime_t *offs_boot)
  */
 ktime_t ktime_get_monotonic_offset(void)
 {
+       struct timekeeper *tk = &timekeeper;
        unsigned long seq;
        struct timespec wtom;
 
        do {
-               seq = read_seqbegin(&timekeeper.lock);
-               wtom = timekeeper.wall_to_monotonic;
-       } while (read_seqretry(&timekeeper.lock, seq));
+               seq = read_seqbegin(&tk->lock);
+               wtom = tk->wall_to_monotonic;
+       } while (read_seqretry(&tk->lock, seq));
 
        return timespec_to_ktime(wtom);
 }
 EXPORT_SYMBOL_GPL(ktime_get_monotonic_offset);
 
-
 /**
  * xtime_update() - advances the timekeeping infrastructure
  * @ticks:     number of ticks, that have elapsed since the last call.