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Diffstat (limited to 'kernel')
-rw-r--r--kernel/time/tick-sched.c83
1 files changed, 29 insertions, 54 deletions
diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
index dc586c3..0f07ff2 100644
--- a/kernel/time/tick-sched.c
+++ b/kernel/time/tick-sched.c
@@ -565,6 +565,20 @@ u64 get_cpu_iowait_time_us(int cpu, u64 *last_update_time)
}
EXPORT_SYMBOL_GPL(get_cpu_iowait_time_us);
+static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
+{
+ hrtimer_cancel(&ts->sched_timer);
+ hrtimer_set_expires(&ts->sched_timer, ts->last_tick);
+
+ /* Forward the time to expire in the future */
+ hrtimer_forward(&ts->sched_timer, now, tick_period);
+
+ if (ts->nohz_mode == NOHZ_MODE_HIGHRES)
+ hrtimer_start_expires(&ts->sched_timer, HRTIMER_MODE_ABS_PINNED);
+ else
+ tick_program_event(hrtimer_get_expires(&ts->sched_timer), 1);
+}
+
static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
ktime_t now, int cpu)
{
@@ -691,22 +705,18 @@ static ktime_t tick_nohz_stop_sched_tick(struct tick_sched *ts,
if (ts->nohz_mode == NOHZ_MODE_HIGHRES)
hrtimer_cancel(&ts->sched_timer);
goto out;
- }
+ }
- if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
- hrtimer_start(&ts->sched_timer, expires,
- HRTIMER_MODE_ABS_PINNED);
- goto out;
- } else if (!tick_program_event(expires, 0))
- goto out;
- /*
- * We are past the event already. So we crossed a
- * jiffie boundary. Update jiffies and raise the
- * softirq.
- */
- tick_do_update_jiffies64(ktime_get());
+ if (ts->nohz_mode == NOHZ_MODE_HIGHRES)
+ hrtimer_start(&ts->sched_timer, expires,
+ HRTIMER_MODE_ABS_PINNED);
+ else
+ tick_program_event(expires, 1);
+ } else {
+ /* Tick is stopped, but required now. Enforce it */
+ tick_nohz_restart(ts, now);
}
- raise_softirq_irqoff(TIMER_SOFTIRQ);
+
out:
ts->next_jiffies = next_jiffies;
ts->last_jiffies = last_jiffies;
@@ -874,30 +884,6 @@ ktime_t tick_nohz_get_sleep_length(void)
return ts->sleep_length;
}
-static void tick_nohz_restart(struct tick_sched *ts, ktime_t now)
-{
- hrtimer_cancel(&ts->sched_timer);
- hrtimer_set_expires(&ts->sched_timer, ts->last_tick);
-
- while (1) {
- /* Forward the time to expire in the future */
- hrtimer_forward(&ts->sched_timer, now, tick_period);
-
- if (ts->nohz_mode == NOHZ_MODE_HIGHRES) {
- hrtimer_start_expires(&ts->sched_timer,
- HRTIMER_MODE_ABS_PINNED);
- break;
- } else {
- if (!tick_program_event(
- hrtimer_get_expires(&ts->sched_timer), 0))
- break;
- }
- /* Reread time and update jiffies */
- now = ktime_get();
- tick_do_update_jiffies64(now);
- }
-}
-
static void tick_nohz_restart_sched_tick(struct tick_sched *ts, ktime_t now)
{
/* Update jiffies first */
@@ -968,12 +954,6 @@ void tick_nohz_idle_exit(void)
local_irq_enable();
}
-static int tick_nohz_reprogram(struct tick_sched *ts, ktime_t now)
-{
- hrtimer_forward(&ts->sched_timer, now, tick_period);
- return tick_program_event(hrtimer_get_expires(&ts->sched_timer), 0);
-}
-
/*
* The nohz low res interrupt handler
*/
@@ -992,10 +972,8 @@ static void tick_nohz_handler(struct clock_event_device *dev)
if (unlikely(ts->tick_stopped))
return;
- while (tick_nohz_reprogram(ts, now)) {
- now = ktime_get();
- tick_do_update_jiffies64(now);
- }
+ hrtimer_forward(&ts->sched_timer, now, tick_period);
+ tick_program_event(hrtimer_get_expires(&ts->sched_timer), 1);
}
/**
@@ -1025,12 +1003,9 @@ static void tick_nohz_switch_to_nohz(void)
/* Get the next period */
next = tick_init_jiffy_update();
- for (;;) {
- hrtimer_set_expires(&ts->sched_timer, next);
- if (!tick_program_event(next, 0))
- break;
- next = ktime_add(next, tick_period);
- }
+ hrtimer_forward_now(&ts->sched_timer, tick_period);
+ hrtimer_set_expires(&ts->sched_timer, next);
+ tick_program_event(next, 1);
local_irq_enable();
}