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Merge branch 'nohz/core' of git://github.com/fweisbec/linux-dynticks …
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…into timers/core

Pull uncontroversial cleanup/refactoring nohz patches from Frederic Weisbecker.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Ingo Molnar committed Oct 21, 2012
2 parents 6f0c058 + 94a5714 commit 0acfd00
Showing 1 changed file with 48 additions and 63 deletions.
111 changes: 48 additions & 63 deletions kernel/time/tick-sched.c
Original file line number Diff line number Diff line change
Expand Up @@ -98,6 +98,49 @@ static ktime_t tick_init_jiffy_update(void)
return period;
}


static void tick_sched_do_timer(ktime_t now)
{
int cpu = smp_processor_id();

#ifdef CONFIG_NO_HZ
/*
* Check if the do_timer duty was dropped. We don't care about
* concurrency: This happens only when the cpu in charge went
* into a long sleep. If two cpus happen to assign themself to
* this duty, then the jiffies update is still serialized by
* xtime_lock.
*/
if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE))
tick_do_timer_cpu = cpu;
#endif

/* Check, if the jiffies need an update */
if (tick_do_timer_cpu == cpu)
tick_do_update_jiffies64(now);
}

static void tick_sched_handle(struct tick_sched *ts, struct pt_regs *regs)
{
#ifdef CONFIG_NO_HZ
/*
* When we are idle and the tick is stopped, we have to touch
* the watchdog as we might not schedule for a really long
* time. This happens on complete idle SMP systems while
* waiting on the login prompt. We also increment the "start of
* idle" jiffy stamp so the idle accounting adjustment we do
* when we go busy again does not account too much ticks.
*/
if (ts->tick_stopped) {
touch_softlockup_watchdog();
if (is_idle_task(current))
ts->idle_jiffies++;
}
#endif
update_process_times(user_mode(regs));
profile_tick(CPU_PROFILING);
}

/*
* NOHZ - aka dynamic tick functionality
*/
Expand Down Expand Up @@ -648,40 +691,12 @@ static void tick_nohz_handler(struct clock_event_device *dev)
{
struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched);
struct pt_regs *regs = get_irq_regs();
int cpu = smp_processor_id();
ktime_t now = ktime_get();

dev->next_event.tv64 = KTIME_MAX;

/*
* Check if the do_timer duty was dropped. We don't care about
* concurrency: This happens only when the cpu in charge went
* into a long sleep. If two cpus happen to assign themself to
* this duty, then the jiffies update is still serialized by
* xtime_lock.
*/
if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE))
tick_do_timer_cpu = cpu;

/* Check, if the jiffies need an update */
if (tick_do_timer_cpu == cpu)
tick_do_update_jiffies64(now);

/*
* When we are idle and the tick is stopped, we have to touch
* the watchdog as we might not schedule for a really long
* time. This happens on complete idle SMP systems while
* waiting on the login prompt. We also increment the "start
* of idle" jiffy stamp so the idle accounting adjustment we
* do when we go busy again does not account too much ticks.
*/
if (ts->tick_stopped) {
touch_softlockup_watchdog();
ts->idle_jiffies++;
}

update_process_times(user_mode(regs));
profile_tick(CPU_PROFILING);
tick_sched_do_timer(now);
tick_sched_handle(ts, regs);

while (tick_nohz_reprogram(ts, now)) {
now = ktime_get();
Expand Down Expand Up @@ -802,45 +817,15 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer)
container_of(timer, struct tick_sched, sched_timer);
struct pt_regs *regs = get_irq_regs();
ktime_t now = ktime_get();
int cpu = smp_processor_id();

#ifdef CONFIG_NO_HZ
/*
* Check if the do_timer duty was dropped. We don't care about
* concurrency: This happens only when the cpu in charge went
* into a long sleep. If two cpus happen to assign themself to
* this duty, then the jiffies update is still serialized by
* xtime_lock.
*/
if (unlikely(tick_do_timer_cpu == TICK_DO_TIMER_NONE))
tick_do_timer_cpu = cpu;
#endif

/* Check, if the jiffies need an update */
if (tick_do_timer_cpu == cpu)
tick_do_update_jiffies64(now);
tick_sched_do_timer(now);

/*
* Do not call, when we are not in irq context and have
* no valid regs pointer
*/
if (regs) {
/*
* When we are idle and the tick is stopped, we have to touch
* the watchdog as we might not schedule for a really long
* time. This happens on complete idle SMP systems while
* waiting on the login prompt. We also increment the "start of
* idle" jiffy stamp so the idle accounting adjustment we do
* when we go busy again does not account too much ticks.
*/
if (ts->tick_stopped) {
touch_softlockup_watchdog();
if (is_idle_task(current))
ts->idle_jiffies++;
}
update_process_times(user_mode(regs));
profile_tick(CPU_PROFILING);
}
if (regs)
tick_sched_handle(ts, regs);

hrtimer_forward(timer, now, tick_period);

Expand Down

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