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-rw-r--r--kernel/time/hrtimer.c108
1 files changed, 50 insertions, 58 deletions
diff --git a/kernel/time/hrtimer.c b/kernel/time/hrtimer.c
index 37e50aadd471..b663653a5d5b 100644
--- a/kernel/time/hrtimer.c
+++ b/kernel/time/hrtimer.c
@@ -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)
+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 @@ retry:
* 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 ? */