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[PATCH] fix next_timer_interrupt() for hrtimer
Also from Thomas Gleixner <tglx@linutronix.de>
Function next_timer_interrupt() got broken with a recent patch
6ba1b91213
as sys_nanosleep() was moved to
hrtimer. This broke things as next_timer_interrupt() did not check hrtimer
tree for next event.
Function next_timer_interrupt() is needed with dyntick (CONFIG_NO_IDLE_HZ,
VST) implementations, as the system can be in idle when next hrtimer event
was supposed to happen. At least ARM and S390 currently use
next_timer_interrupt().
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
parent
f7c09bd972
commit
69239749e1
@ -422,12 +422,14 @@ static int timer_dyn_tick_disable(void)
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void timer_dyn_reprogram(void)
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{
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struct dyn_tick_timer *dyn_tick = system_timer->dyn_tick;
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unsigned long next, seq;
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if (dyn_tick) {
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write_seqlock(&xtime_lock);
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if (dyn_tick->state & DYN_TICK_ENABLED)
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if (dyn_tick && (dyn_tick->state & DYN_TICK_ENABLED)) {
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next = next_timer_interrupt();
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do {
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seq = read_seqbegin(&xtime_lock);
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dyn_tick->reprogram(next_timer_interrupt() - jiffies);
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write_sequnlock(&xtime_lock);
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} while (read_seqretry(&xtime_lock, seq));
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}
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}
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@ -116,6 +116,10 @@ extern int hrtimer_try_to_cancel(struct hrtimer *timer);
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extern ktime_t hrtimer_get_remaining(const struct hrtimer *timer);
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extern int hrtimer_get_res(const clockid_t which_clock, struct timespec *tp);
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#ifdef CONFIG_NO_IDLE_HZ
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extern ktime_t hrtimer_get_next_event(void);
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#endif
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static inline int hrtimer_active(const struct hrtimer *timer)
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{
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return timer->state == HRTIMER_PENDING;
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@ -505,6 +505,41 @@ ktime_t hrtimer_get_remaining(const struct hrtimer *timer)
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return rem;
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}
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#ifdef CONFIG_NO_IDLE_HZ
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/**
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* hrtimer_get_next_event - get the time until next expiry event
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*
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* Returns the delta to the next expiry event or KTIME_MAX if no timer
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* is pending.
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*/
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ktime_t hrtimer_get_next_event(void)
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{
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struct hrtimer_base *base = __get_cpu_var(hrtimer_bases);
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ktime_t delta, mindelta = { .tv64 = KTIME_MAX };
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unsigned long flags;
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int i;
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for (i = 0; i < MAX_HRTIMER_BASES; i++, base++) {
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struct hrtimer *timer;
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spin_lock_irqsave(&base->lock, flags);
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if (!base->first) {
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spin_unlock_irqrestore(&base->lock, flags);
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continue;
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}
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timer = rb_entry(base->first, struct hrtimer, node);
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delta.tv64 = timer->expires.tv64;
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spin_unlock_irqrestore(&base->lock, flags);
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delta = ktime_sub(delta, base->get_time());
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if (delta.tv64 < mindelta.tv64)
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mindelta.tv64 = delta.tv64;
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}
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if (mindelta.tv64 < 0)
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mindelta.tv64 = 0;
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return mindelta;
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}
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#endif
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/**
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* hrtimer_init - initialize a timer to the given clock
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*
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@ -489,9 +489,21 @@ unsigned long next_timer_interrupt(void)
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struct list_head *list;
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struct timer_list *nte;
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unsigned long expires;
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unsigned long hr_expires = MAX_JIFFY_OFFSET;
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ktime_t hr_delta;
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tvec_t *varray[4];
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int i, j;
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hr_delta = hrtimer_get_next_event();
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if (hr_delta.tv64 != KTIME_MAX) {
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struct timespec tsdelta;
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tsdelta = ktime_to_timespec(hr_delta);
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hr_expires = timespec_to_jiffies(&tsdelta);
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if (hr_expires < 3)
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return hr_expires + jiffies;
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}
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hr_expires += jiffies;
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base = &__get_cpu_var(tvec_bases);
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spin_lock(&base->t_base.lock);
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expires = base->timer_jiffies + (LONG_MAX >> 1);
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@ -542,6 +554,10 @@ found:
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}
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}
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spin_unlock(&base->t_base.lock);
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if (time_before(hr_expires, expires))
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return hr_expires;
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return expires;
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}
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#endif
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