diff options
Diffstat (limited to 'kernel/time')
| -rw-r--r-- | kernel/time/clockevents.c | 3 | ||||
| -rw-r--r-- | kernel/time/tick-sched.c | 18 |
2 files changed, 19 insertions, 2 deletions
diff --git a/kernel/time/clockevents.c b/kernel/time/clockevents.c index 9cd928f7a7c6..7e1ce012a851 100644 --- a/kernel/time/clockevents.c +++ b/kernel/time/clockevents.c @@ -297,8 +297,7 @@ void clockevents_register_device(struct clock_event_device *dev) } EXPORT_SYMBOL_GPL(clockevents_register_device); -static void clockevents_config(struct clock_event_device *dev, - u32 freq) +void clockevents_config(struct clock_event_device *dev, u32 freq) { u64 sec; diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 0c927cd85345..da70c6db496c 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -815,6 +815,16 @@ static enum hrtimer_restart tick_sched_timer(struct hrtimer *timer) return HRTIMER_RESTART; } +static int sched_skew_tick; + +static int __init skew_tick(char *str) +{ + get_option(&str, &sched_skew_tick); + + return 0; +} +early_param("skew_tick", skew_tick); + /** * tick_setup_sched_timer - setup the tick emulation timer */ @@ -832,6 +842,14 @@ void tick_setup_sched_timer(void) /* Get the next period (per cpu) */ hrtimer_set_expires(&ts->sched_timer, tick_init_jiffy_update()); + /* Offset the tick to avert xtime_lock contention. */ + if (sched_skew_tick) { + u64 offset = ktime_to_ns(tick_period) >> 1; + do_div(offset, num_possible_cpus()); + offset *= smp_processor_id(); + hrtimer_add_expires_ns(&ts->sched_timer, offset); + } + for (;;) { hrtimer_forward(&ts->sched_timer, now, tick_period); hrtimer_start_expires(&ts->sched_timer, |