diff options
Diffstat (limited to 'kernel/watchdog.c')
| -rw-r--r-- | kernel/watchdog.c | 28 |
1 files changed, 20 insertions, 8 deletions
diff --git a/kernel/watchdog.c b/kernel/watchdog.c index 7f21591c8ec5..f2813e137b23 100644 --- a/kernel/watchdog.c +++ b/kernel/watchdog.c @@ -588,17 +588,13 @@ static void watchdog_set_prio(unsigned int policy, unsigned int prio) sched_setscheduler(current, policy, ¶m); } -/* Must be called with hotplug lock (lock_device_hotplug()) held. */ void watchdog_enable(unsigned int cpu) { struct hrtimer *hrtimer = raw_cpu_ptr(&watchdog_hrtimer); unsigned int *enabled = raw_cpu_ptr(&watchdog_en); - lock_device_hotplug_assert(); - if (*enabled) return; - *enabled = 1; /* kick off the timer for the hardlockup detector */ hrtimer_init(hrtimer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); @@ -614,24 +610,40 @@ void watchdog_enable(unsigned int cpu) /* initialize timestamp */ watchdog_set_prio(SCHED_FIFO, MAX_RT_PRIO - 1); __touch_watchdog(); + + /* + * Need to ensure above operations are observed by other CPUs before + * indicating that timer is enabled. This is to synchronize core + * isolation and hotplug. Core isolation will wait for this flag to be + * set. + */ + mb(); + *enabled = 1; } -/* Must be called with hotplug lock (lock_device_hotplug()) held. */ void watchdog_disable(unsigned int cpu) { struct hrtimer *hrtimer = raw_cpu_ptr(&watchdog_hrtimer); unsigned int *enabled = raw_cpu_ptr(&watchdog_en); - lock_device_hotplug_assert(); - if (!*enabled) return; - *enabled = 0; watchdog_set_prio(SCHED_NORMAL, 0); hrtimer_cancel(hrtimer); /* disable the perf event */ watchdog_nmi_disable(cpu); + + /* + * No need for barrier here since disabling the watchdog is + * synchronized with hotplug lock + */ + *enabled = 0; +} + +bool watchdog_configured(unsigned int cpu) +{ + return *per_cpu_ptr(&watchdog_en, cpu); } static void watchdog_cleanup(unsigned int cpu, bool online) |