static void update_timers(int cpu)
{
/*
* Make sure that perf event counter will adopt to a new
* sampling period. Updating the sampling period directly would
* be much nicer but we do not have an API for that now so
* let's use a big hammer.
* Hrtimer will adopt the new period on the next tick but this
* might be late already so we have to restart the timer as well.
*/
watchdog_nmi_disable(cpu);
smp_call_function_single(cpu, restart_watchdog_hrtimer, NULL, 1);
watchdog_nmi_enable(cpu);
}
static void watchdog_enable(unsigned int cpu)
{
struct hrtimer *hrtimer = &__raw_get_cpu_var(watchdog_hrtimer);
/* kick off the timer for the hardlockup detector */
hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer->function = watchdog_timer_fn;
/* Enable the perf event */
watchdog_nmi_enable(cpu);
/* done here because hrtimer_start can only pin to smp_processor_id() */
hrtimer_start(hrtimer, ns_to_ktime(sample_period),
HRTIMER_MODE_REL_PINNED);
/* initialize timestamp */
watchdog_set_prio(SCHED_FIFO, MAX_RT_PRIO - 1);
__touch_watchdog();
}
static void watchdog_enable(unsigned int cpu)
{
struct hrtimer *hrtimer = this_cpu_ptr(&watchdog_hrtimer);
/*
* Start the timer first to prevent the NMI watchdog triggering
* before the timer has a chance to fire.
*/
hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
hrtimer->function = watchdog_timer_fn;
hrtimer_start(hrtimer, ns_to_ktime(sample_period),
HRTIMER_MODE_REL_PINNED);
/* Initialize timestamp */
__touch_watchdog();
/* Enable the perf event */
if (watchdog_enabled & NMI_WATCHDOG_ENABLED)
watchdog_nmi_enable(cpu);
watchdog_set_prio(SCHED_FIFO, MAX_RT_PRIO - 1);
}