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-rw-r--r--include/linux/timer.h6
-rw-r--r--kernel/time/tick-sched.c16
-rw-r--r--kernel/timer.c10
3 files changed, 30 insertions, 2 deletions
diff --git a/include/linux/timer.h b/include/linux/timer.h
index e0c5c16c992f..c661710d3627 100644
--- a/include/linux/timer.h
+++ b/include/linux/timer.h
@@ -69,6 +69,12 @@ extern int __mod_timer(struct timer_list *timer, unsigned long expires);
69extern int mod_timer(struct timer_list *timer, unsigned long expires); 69extern int mod_timer(struct timer_list *timer, unsigned long expires);
70 70
71/* 71/*
72 * The jiffies value which is added to now, when there is no timer
73 * in the timer wheel:
74 */
75#define NEXT_TIMER_MAX_DELTA ((1UL << 30) - 1)
76
77/*
72 * Return when the next timer-wheel timeout occurs (in absolute jiffies), 78 * Return when the next timer-wheel timeout occurs (in absolute jiffies),
73 * locks the timer base: 79 * locks the timer base:
74 */ 80 */
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index 3e7ebc4646b7..52db9e3c526e 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -247,6 +247,21 @@ void tick_nohz_stop_sched_tick(void)
247 if (cpu == tick_do_timer_cpu) 247 if (cpu == tick_do_timer_cpu)
248 tick_do_timer_cpu = -1; 248 tick_do_timer_cpu = -1;
249 249
250 ts->idle_sleeps++;
251
252 /*
253 * delta_jiffies >= NEXT_TIMER_MAX_DELTA signals that
254 * there is no timer pending or at least extremly far
255 * into the future (12 days for HZ=1000). In this case
256 * we simply stop the tick timer:
257 */
258 if (unlikely(delta_jiffies >= NEXT_TIMER_MAX_DELTA)) {
259 ts->idle_expires.tv64 = KTIME_MAX;
260 if (ts->nohz_mode == NOHZ_MODE_HIGHRES)
261 hrtimer_cancel(&ts->sched_timer);
262 goto out;
263 }
264
250 /* 265 /*
251 * calculate the expiry time for the next timer wheel 266 * calculate the expiry time for the next timer wheel
252 * timer 267 * timer
@@ -254,7 +269,6 @@ void tick_nohz_stop_sched_tick(void)
254 expires = ktime_add_ns(last_update, tick_period.tv64 * 269 expires = ktime_add_ns(last_update, tick_period.tv64 *
255 delta_jiffies); 270 delta_jiffies);
256 ts->idle_expires = expires; 271 ts->idle_expires = expires;
257 ts->idle_sleeps++;
258 272
259 if (ts->nohz_mode == NOHZ_MODE_HIGHRES) { 273 if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
260 hrtimer_start(&ts->sched_timer, expires, 274 hrtimer_start(&ts->sched_timer, expires,
diff --git a/kernel/timer.c b/kernel/timer.c
index 5ec5490f8d85..1a69705c2fb9 100644
--- a/kernel/timer.c
+++ b/kernel/timer.c
@@ -666,7 +666,7 @@ static inline void __run_timers(tvec_base_t *base)
666static unsigned long __next_timer_interrupt(tvec_base_t *base) 666static unsigned long __next_timer_interrupt(tvec_base_t *base)
667{ 667{
668 unsigned long timer_jiffies = base->timer_jiffies; 668 unsigned long timer_jiffies = base->timer_jiffies;
669 unsigned long expires = timer_jiffies + (LONG_MAX >> 1); 669 unsigned long expires = timer_jiffies + NEXT_TIMER_MAX_DELTA;
670 int index, slot, array, found = 0; 670 int index, slot, array, found = 0;
671 struct timer_list *nte; 671 struct timer_list *nte;
672 tvec_t *varray[4]; 672 tvec_t *varray[4];
@@ -752,6 +752,14 @@ static unsigned long cmp_next_hrtimer_event(unsigned long now,
752 752
753 tsdelta = ktime_to_timespec(hr_delta); 753 tsdelta = ktime_to_timespec(hr_delta);
754 delta = timespec_to_jiffies(&tsdelta); 754 delta = timespec_to_jiffies(&tsdelta);
755
756 /*
757 * Limit the delta to the max value, which is checked in
758 * tick_nohz_stop_sched_tick():
759 */
760 if (delta > NEXT_TIMER_MAX_DELTA)
761 delta = NEXT_TIMER_MAX_DELTA;
762
755 /* 763 /*
756 * Take rounding errors in to account and make sure, that it 764 * Take rounding errors in to account and make sure, that it
757 * expires in the next tick. Otherwise we go into an endless 765 * expires in the next tick. Otherwise we go into an endless