diff options
| -rw-r--r-- | kernel/time/tick-broadcast.c | 53 |
1 files changed, 25 insertions, 28 deletions
diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index 7e8ca4f448a8..5d9e4aab9797 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -255,18 +255,18 @@ int tick_receive_broadcast(void) /* * Broadcast the event to the cpus, which are set in the mask (mangled). */ -static void tick_do_broadcast(struct cpumask *mask) +static bool tick_do_broadcast(struct cpumask *mask) { int cpu = smp_processor_id(); struct tick_device *td; + bool local = false; /* * Check, if the current cpu is in the mask */ if (cpumask_test_cpu(cpu, mask)) { cpumask_clear_cpu(cpu, mask); - td = &per_cpu(tick_cpu_device, cpu); - td->evtdev->event_handler(td->evtdev); + local = true; } if (!cpumask_empty(mask)) { @@ -279,16 +279,17 @@ static void tick_do_broadcast(struct cpumask *mask) td = &per_cpu(tick_cpu_device, cpumask_first(mask)); td->evtdev->broadcast(mask); } + return local; } /* * Periodic broadcast: * - invoke the broadcast handlers */ -static void tick_do_periodic_broadcast(void) +static bool tick_do_periodic_broadcast(void) { cpumask_and(tmpmask, cpu_online_mask, tick_broadcast_mask); - tick_do_broadcast(tmpmask); + return tick_do_broadcast(tmpmask); } /* @@ -296,34 +297,26 @@ static void tick_do_periodic_broadcast(void) */ static void tick_handle_periodic_broadcast(struct clock_event_device *dev) { - ktime_t next; + struct tick_device *td = this_cpu_ptr(&tick_cpu_device); + bool bc_local; raw_spin_lock(&tick_broadcast_lock); + bc_local = tick_do_periodic_broadcast(); - tick_do_periodic_broadcast(); + if (dev->state == CLOCK_EVT_STATE_ONESHOT) { + ktime_t next = ktime_add(dev->next_event, tick_period); - /* - * The device is in periodic mode. No reprogramming necessary: - */ - if (dev->state == CLOCK_EVT_STATE_PERIODIC) - goto unlock; + clockevents_program_event(dev, next, true); + } + raw_spin_unlock(&tick_broadcast_lock); /* - * Setup the next period for devices, which do not have - * periodic mode. We read dev->next_event first and add to it - * when the event already expired. clockevents_program_event() - * sets dev->next_event only when the event is really - * programmed to the device. + * We run the handler of the local cpu after dropping + * tick_broadcast_lock because the handler might deadlock when + * trying to switch to oneshot mode. */ - for (next = dev->next_event; ;) { - next = ktime_add(next, tick_period); - - if (!clockevents_program_event(dev, next, false)) - goto unlock; - tick_do_periodic_broadcast(); - } -unlock: - raw_spin_unlock(&tick_broadcast_lock); + if (bc_local) + td->evtdev->event_handler(td->evtdev); } /** @@ -622,9 +615,13 @@ again: cpumask_and(tmpmask, tmpmask, cpu_online_mask); /* - * Wakeup the cpus which have an expired event. + * Wakeup the cpus which have an expired event and handle the + * broadcast event of the local cpu. */ - tick_do_broadcast(tmpmask); + if (tick_do_broadcast(tmpmask)) { + td = this_cpu_ptr(&tick_cpu_device); + td->evtdev->event_handler(td->evtdev); + } /* * Two reasons for reprogram: |