diff options
Diffstat (limited to 'kernel/watchdog_buddy.c')
| -rw-r--r-- | kernel/watchdog_buddy.c | 21 |
1 files changed, 21 insertions, 0 deletions
diff --git a/kernel/watchdog_buddy.c b/kernel/watchdog_buddy.c index 2ef88722c5e7..34dbfe091f4b 100644 --- a/kernel/watchdog_buddy.c +++ b/kernel/watchdog_buddy.c @@ -51,6 +51,13 @@ void watchdog_hardlockup_enable(unsigned int cpu) if (next_cpu < nr_cpu_ids) watchdog_hardlockup_touch_cpu(next_cpu); + /* + * Makes sure that watchdog is touched on this CPU before + * other CPUs could see it in watchdog_cpus. The counter + * part is in watchdog_buddy_check_hardlockup(). + */ + smp_wmb(); + cpumask_set_cpu(cpu, &watchdog_cpus); } @@ -68,6 +75,13 @@ void watchdog_hardlockup_disable(unsigned int cpu) if (next_cpu < nr_cpu_ids) watchdog_hardlockup_touch_cpu(next_cpu); + /* + * Makes sure that watchdog is touched on the next CPU before + * this CPU disappear in watchdog_cpus. The counter part is in + * watchdog_buddy_check_hardlockup(). + */ + smp_wmb(); + cpumask_clear_cpu(cpu, &watchdog_cpus); } @@ -88,5 +102,12 @@ void watchdog_buddy_check_hardlockup(int hrtimer_interrupts) if (next_cpu >= nr_cpu_ids) return; + /* + * Make sure that the watchdog was touched on next CPU when + * watchdog_next_cpu() returned another one because of + * a change in watchdog_hardlockup_enable()/disable(). + */ + smp_rmb(); + watchdog_hardlockup_check(next_cpu, NULL); } |