diff options
Diffstat (limited to 'kernel/softlockup.c')
| -rw-r--r-- | kernel/softlockup.c | 69 |
1 files changed, 42 insertions, 27 deletions
diff --git a/kernel/softlockup.c b/kernel/softlockup.c index 81324d12eb35..0d4c7898ab80 100644 --- a/kernel/softlockup.c +++ b/kernel/softlockup.c @@ -22,9 +22,10 @@ static DEFINE_SPINLOCK(print_lock); -static DEFINE_PER_CPU(unsigned long, touch_timestamp); -static DEFINE_PER_CPU(unsigned long, print_timestamp); -static DEFINE_PER_CPU(struct task_struct *, watchdog_task); +static DEFINE_PER_CPU(unsigned long, softlockup_touch_ts); /* touch timestamp */ +static DEFINE_PER_CPU(unsigned long, softlockup_print_ts); /* print timestamp */ +static DEFINE_PER_CPU(struct task_struct *, softlockup_watchdog); +static DEFINE_PER_CPU(bool, softlock_touch_sync); static int __read_mostly did_panic; int __read_mostly softlockup_thresh = 60; @@ -70,22 +71,28 @@ static void __touch_softlockup_watchdog(void) { int this_cpu = raw_smp_processor_id(); - __raw_get_cpu_var(touch_timestamp) = get_timestamp(this_cpu); + __raw_get_cpu_var(softlockup_touch_ts) = get_timestamp(this_cpu); } void touch_softlockup_watchdog(void) { - __raw_get_cpu_var(touch_timestamp) = 0; + __raw_get_cpu_var(softlockup_touch_ts) = 0; } EXPORT_SYMBOL(touch_softlockup_watchdog); +void touch_softlockup_watchdog_sync(void) +{ + __raw_get_cpu_var(softlock_touch_sync) = true; + __raw_get_cpu_var(softlockup_touch_ts) = 0; +} + void touch_all_softlockup_watchdogs(void) { int cpu; /* Cause each CPU to re-update its timestamp rather than complain */ for_each_online_cpu(cpu) - per_cpu(touch_timestamp, cpu) = 0; + per_cpu(softlockup_touch_ts, cpu) = 0; } EXPORT_SYMBOL(touch_all_softlockup_watchdogs); @@ -104,28 +111,36 @@ int proc_dosoftlockup_thresh(struct ctl_table *table, int write, void softlockup_tick(void) { int this_cpu = smp_processor_id(); - unsigned long touch_timestamp = per_cpu(touch_timestamp, this_cpu); - unsigned long print_timestamp; + unsigned long touch_ts = per_cpu(softlockup_touch_ts, this_cpu); + unsigned long print_ts; struct pt_regs *regs = get_irq_regs(); unsigned long now; /* Is detection switched off? */ - if (!per_cpu(watchdog_task, this_cpu) || softlockup_thresh <= 0) { + if (!per_cpu(softlockup_watchdog, this_cpu) || softlockup_thresh <= 0) { /* Be sure we don't false trigger if switched back on */ - if (touch_timestamp) - per_cpu(touch_timestamp, this_cpu) = 0; + if (touch_ts) + per_cpu(softlockup_touch_ts, this_cpu) = 0; return; } - if (touch_timestamp == 0) { + if (touch_ts == 0) { + if (unlikely(per_cpu(softlock_touch_sync, this_cpu))) { + /* + * If the time stamp was touched atomically + * make sure the scheduler tick is up to date. + */ + per_cpu(softlock_touch_sync, this_cpu) = false; + sched_clock_tick(); + } __touch_softlockup_watchdog(); return; } - print_timestamp = per_cpu(print_timestamp, this_cpu); + print_ts = per_cpu(softlockup_print_ts, this_cpu); /* report at most once a second */ - if (print_timestamp == touch_timestamp || did_panic) + if (print_ts == touch_ts || did_panic) return; /* do not print during early bootup: */ @@ -140,18 +155,18 @@ void softlockup_tick(void) * Wake up the high-prio watchdog task twice per * threshold timespan. */ - if (now > touch_timestamp + softlockup_thresh/2) - wake_up_process(per_cpu(watchdog_task, this_cpu)); + if (now > touch_ts + softlockup_thresh/2) + wake_up_process(per_cpu(softlockup_watchdog, this_cpu)); /* Warn about unreasonable delays: */ - if (now <= (touch_timestamp + softlockup_thresh)) + if (now <= (touch_ts + softlockup_thresh)) return; - per_cpu(print_timestamp, this_cpu) = touch_timestamp; + per_cpu(softlockup_print_ts, this_cpu) = touch_ts; spin_lock(&print_lock); printk(KERN_ERR "BUG: soft lockup - CPU#%d stuck for %lus! [%s:%d]\n", - this_cpu, now - touch_timestamp, + this_cpu, now - touch_ts, current->comm, task_pid_nr(current)); print_modules(); print_irqtrace_events(current); @@ -209,32 +224,32 @@ cpu_callback(struct notifier_block *nfb, unsigned long action, void *hcpu) switch (action) { case CPU_UP_PREPARE: case CPU_UP_PREPARE_FROZEN: - BUG_ON(per_cpu(watchdog_task, hotcpu)); + BUG_ON(per_cpu(softlockup_watchdog, hotcpu)); p = kthread_create(watchdog, hcpu, "watchdog/%d", hotcpu); if (IS_ERR(p)) { printk(KERN_ERR "watchdog for %i failed\n", hotcpu); return NOTIFY_BAD; } - per_cpu(touch_timestamp, hotcpu) = 0; - per_cpu(watchdog_task, hotcpu) = p; + per_cpu(softlockup_touch_ts, hotcpu) = 0; + per_cpu(softlockup_watchdog, hotcpu) = p; kthread_bind(p, hotcpu); break; case CPU_ONLINE: case CPU_ONLINE_FROZEN: - wake_up_process(per_cpu(watchdog_task, hotcpu)); + wake_up_process(per_cpu(softlockup_watchdog, hotcpu)); break; #ifdef CONFIG_HOTPLUG_CPU case CPU_UP_CANCELED: case CPU_UP_CANCELED_FROZEN: - if (!per_cpu(watchdog_task, hotcpu)) + if (!per_cpu(softlockup_watchdog, hotcpu)) break; /* Unbind so it can run. Fall thru. */ - kthread_bind(per_cpu(watchdog_task, hotcpu), + kthread_bind(per_cpu(softlockup_watchdog, hotcpu), cpumask_any(cpu_online_mask)); case CPU_DEAD: case CPU_DEAD_FROZEN: - p = per_cpu(watchdog_task, hotcpu); - per_cpu(watchdog_task, hotcpu) = NULL; + p = per_cpu(softlockup_watchdog, hotcpu); + per_cpu(softlockup_watchdog, hotcpu) = NULL; kthread_stop(p); break; #endif /* CONFIG_HOTPLUG_CPU */ |