diff options
Diffstat (limited to 'kernel/watchdog.c')
| -rw-r--r-- | kernel/watchdog.c | 35 |
1 files changed, 17 insertions, 18 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index c8c21be11ab..4a944676358 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -23,6 +23,7 @@ #include <linux/module.h> #include <linux/sysctl.h> #include <linux/smpboot.h> +#include <linux/sched/rt.h> #include <asm/irq_regs.h> #include <linux/kvm_para.h> @@ -31,6 +32,7 @@ int watchdog_enabled = 1; int __read_mostly watchdog_thresh = 10; static int __read_mostly watchdog_disabled; +static u64 __read_mostly sample_period; static DEFINE_PER_CPU(unsigned long, watchdog_touch_ts); static DEFINE_PER_CPU(struct task_struct *, softlockup_watchdog); @@ -111,12 +113,12 @@ static int get_softlockup_thresh(void) * resolution, and we don't need to waste time with a big divide when * 2^30ns == 1.074s. */ -static unsigned long get_timestamp(int this_cpu) +static unsigned long get_timestamp(void) { - return cpu_clock(this_cpu) >> 30LL; /* 2^30 ~= 10^9 */ + return local_clock() >> 30LL; /* 2^30 ~= 10^9 */ } -static u64 get_sample_period(void) +static void set_sample_period(void) { /* * convert watchdog_thresh from seconds to ns @@ -125,15 +127,13 @@ static u64 get_sample_period(void) * and hard thresholds) to increment before the * hardlockup detector generates a warning */ - return get_softlockup_thresh() * ((u64)NSEC_PER_SEC / 5); + sample_period = get_softlockup_thresh() * ((u64)NSEC_PER_SEC / 5); } /* Commands for resetting the watchdog */ static void __touch_watchdog(void) { - int this_cpu = smp_processor_id(); - - __this_cpu_write(watchdog_touch_ts, get_timestamp(this_cpu)); + __this_cpu_write(watchdog_touch_ts, get_timestamp()); } void touch_softlockup_watchdog(void) @@ -194,7 +194,7 @@ static int is_hardlockup(void) static int is_softlockup(unsigned long touch_ts) { - unsigned long now = get_timestamp(smp_processor_id()); + unsigned long now = get_timestamp(); /* Warn about unreasonable delays: */ if (time_after(now, touch_ts + get_softlockup_thresh())) @@ -275,7 +275,7 @@ static enum hrtimer_restart watchdog_timer_fn(struct hrtimer *hrtimer) wake_up_process(__this_cpu_read(softlockup_watchdog)); /* .. and repeat */ - hrtimer_forward_now(hrtimer, ns_to_ktime(get_sample_period())); + hrtimer_forward_now(hrtimer, ns_to_ktime(sample_period)); if (touch_ts == 0) { if (unlikely(__this_cpu_read(softlockup_touch_sync))) { @@ -343,6 +343,10 @@ 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; + if (!watchdog_enabled) { kthread_park(current); return; @@ -351,12 +355,8 @@ static void watchdog_enable(unsigned int cpu) /* Enable the perf event */ watchdog_nmi_enable(cpu); - /* kick off the timer for the hardlockup detector */ - hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - hrtimer->function = watchdog_timer_fn; - /* done here because hrtimer_start can only pin to smp_processor_id() */ - hrtimer_start(hrtimer, ns_to_ktime(get_sample_period()), + hrtimer_start(hrtimer, ns_to_ktime(sample_period), HRTIMER_MODE_REL_PINNED); /* initialize timestamp */ @@ -368,9 +368,6 @@ static void watchdog_disable(unsigned int cpu) { struct hrtimer *hrtimer = &__raw_get_cpu_var(watchdog_hrtimer); - if (!watchdog_enabled) - return; - watchdog_set_prio(SCHED_NORMAL, 0); hrtimer_cancel(hrtimer); /* disable the perf event */ @@ -386,7 +383,7 @@ static int watchdog_should_run(unsigned int cpu) /* * The watchdog thread function - touches the timestamp. * - * It only runs once every get_sample_period() seconds (4 seconds by + * It only runs once every sample_period seconds (4 seconds by * default) to reset the softlockup timestamp. If this gets delayed * for more than 2*watchdog_thresh seconds then the debug-printout * triggers in watchdog_timer_fn(). @@ -519,6 +516,7 @@ int proc_dowatchdog(struct ctl_table *table, int write, if (ret || !write) return ret; + set_sample_period(); if (watchdog_enabled && watchdog_thresh) watchdog_enable_all_cpus(); else @@ -540,6 +538,7 @@ static struct smp_hotplug_thread watchdog_threads = { void __init lockup_detector_init(void) { + set_sample_period(); if (smpboot_register_percpu_thread(&watchdog_threads)) { pr_err("Failed to create watchdog threads, disabled\n"); watchdog_disabled = -ENODEV; |