Linus, please pull the latest timers-urgent-for-linus git tree from: git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git timers-urgent-for-linus Viresh unearthed the following three hickups in the timer/timekeeping code: - Negated check for the result of a clock event selection - A missing early exit in the jiffies update path which causes update_wall_time to be called for nothing causing lock contention and wasted cycles in the timer interrupt - Checking a variable in the NOHZ code enable code for true which can only be set by that very code after the check succeeds. That results in a rock solid runtime disablement of that feature. Thanks, tglx ------------------> Viresh Kumar (3): tick-common: Fix wrong check in tick_check_replacement() tick-sched: Don't call update_wall_time() when delta is lesser than tick_period tick-sched: Check tick_nohz_enabled in tick_nohz_switch_to_nohz() kernel/time/tick-common.c | 2 +- kernel/time/tick-sched.c | 5 ++++- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/kernel/time/tick-common.c b/kernel/time/tick-common.c index 0156612..0a0608e 100644 --- a/kernel/time/tick-common.c +++ b/kernel/time/tick-common.c @@ -276,7 +276,7 @@ static bool tick_check_preferred(struct clock_event_device *curdev, bool tick_check_replacement(struct clock_event_device *curdev, struct clock_event_device *newdev) { - if (tick_check_percpu(curdev, newdev, smp_processor_id())) + if (!tick_check_percpu(curdev, newdev, smp_processor_id())) return false; return tick_check_preferred(curdev, newdev); diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c index 9f8af69..6558b7a 100644 --- a/kernel/time/tick-sched.c +++ b/kernel/time/tick-sched.c @@ -84,6 +84,9 @@ static void tick_do_update_jiffies64(ktime_t now) /* Keep the tick_next_period variable up to date */ tick_next_period = ktime_add(last_jiffies_update, tick_period); + } else { + write_sequnlock(&jiffies_lock); + return; } write_sequnlock(&jiffies_lock); update_wall_time(); @@ -967,7 +970,7 @@ static void tick_nohz_switch_to_nohz(void) struct tick_sched *ts = &__get_cpu_var(tick_cpu_sched); ktime_t next; - if (!tick_nohz_active) + if (!tick_nohz_enabled) return; local_irq_disable(); -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/