diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/time/tick-broadcast.c | 28 |
1 files changed, 26 insertions, 2 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 380910db7157..005c0ca81a32 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -392,6 +392,7 @@ int tick_resume_broadcast(void) #ifdef CONFIG_TICK_ONESHOT static cpumask_var_t tick_broadcast_oneshot_mask; +static cpumask_var_t tick_broadcast_pending_mask; /* * Exposed for debugging: see timer_list.c @@ -470,6 +471,12 @@ again: td = &per_cpu(tick_cpu_device, cpu); if (td->evtdev->next_event.tv64 <= now.tv64) { cpumask_set_cpu(cpu, tmpmask); + /* + * Mark the remote cpu in the pending mask, so + * it can avoid reprogramming the cpu local + * timer in tick_broadcast_oneshot_control(). + */ + cpumask_set_cpu(cpu, tick_broadcast_pending_mask); } else if (td->evtdev->next_event.tv64 < next_event.tv64) { next_event.tv64 = td->evtdev->next_event.tv64; next_cpu = cpu; @@ -535,6 +542,7 @@ void tick_broadcast_oneshot_control(unsigned long reason) raw_spin_lock_irqsave(&tick_broadcast_lock, flags); if (reason == CLOCK_EVT_NOTIFY_BROADCAST_ENTER) { + WARN_ON_ONCE(cpumask_test_cpu(cpu, tick_broadcast_pending_mask)); if (!cpumask_test_and_set_cpu(cpu, tick_broadcast_oneshot_mask)) { clockevents_set_mode(dev, CLOCK_EVT_MODE_SHUTDOWN); if (dev->next_event.tv64 < bc->next_event.tv64) @@ -543,10 +551,25 @@ void tick_broadcast_oneshot_control(unsigned long reason) } else { if (cpumask_test_and_clear_cpu(cpu, tick_broadcast_oneshot_mask)) { clockevents_set_mode(dev, CLOCK_EVT_MODE_ONESHOT); - if (dev->next_event.tv64 != KTIME_MAX) - tick_program_event(dev->next_event, 1); + if (dev->next_event.tv64 == KTIME_MAX) + goto out; + /* + * The cpu which was handling the broadcast + * timer marked this cpu in the broadcast + * pending mask and fired the broadcast + * IPI. So we are going to handle the expired + * event anyway via the broadcast IPI + * handler. No need to reprogram the timer + * with an already expired event. + */ + if (cpumask_test_and_clear_cpu(cpu, + tick_broadcast_pending_mask)) + goto out; + + tick_program_event(dev->next_event, 1); } } +out: raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags); } @@ -683,5 +706,6 @@ void __init tick_broadcast_init(void) alloc_cpumask_var(&tmpmask, GFP_NOWAIT); #ifdef CONFIG_TICK_ONESHOT alloc_cpumask_var(&tick_broadcast_oneshot_mask, GFP_NOWAIT); + alloc_cpumask_var(&tick_broadcast_pending_mask, GFP_NOWAIT); #endif } |